a microbiologist is preparing a medium on which to culture e. coli bacteria. she buffers the medium at ph 7.00 to minimize the effect of acid-producing fermentation. what volumes of equimolar aqueous solutions of k2hpo4 and kh2po4 must she combine to make 700.0 ml of the ph 7.00 buffer? ka values for phosphoric acid: ka1

Answers

Answer 1

The microbiologist needs to combine 9.39 mL of equimolar K2HPO4 and 690.61 mL of equimolar KH2PO4 to make 700.0 mL of pH 7.00 buffer.

To set up the pH 7.00 cushion, the microbiologist needs to consolidate equimolar measures of the corrosive (H2PO4-) and its form base (HPO42-), which can be accomplished utilizing the Henderson-Hasselbalch condition:

pH = pKa + log([A-]/[HA])

Where pH is the ideal pH of the cradle, pKa is the corrosive separation steady of the corrosive, and [A-]/[HA] is the proportion of the centralizations of the form base to the corrosive.

For this situation, the pKa1 an incentive for phosphoric corrosive is 2.15. Since the cushion should be arranged utilizing equimolar measures of K2HPO4 and KH2PO4, the [A-]/[HA] proportion is 1. Consequently, we can rework the Henderson-Hasselbalch condition to address for the proportion of the volumes of the two arrangements:

[V(HPO42-)/V(H2PO4-)] = [A-]/[HA] = 1

Subbing the pKa worth and settling for the proportion, we get:

[V(HPO42-)/V(H2PO4-)] = [tex]10^(pH-pKa)[/tex] = [tex]10^(7.00-2.15)[/tex] = 73.5

Since the volumes of the two arrangements should amount to 700.0 mL, we can communicate the volume of one arrangement as far as the other:

V(H2PO4-) = 700.0 mL/(1 + 73.5) = 9.39 mL

V(HPO42-) = 700.0 mL - V(H2PO4-) = 690.61 mL

Thusly, the microbiologist needs to consolidate 9.39 mL of the equimolar K2HPO4 arrangement with 690.61 mL of the equimolar KH2PO4 answer for get ready 700.0 mL of the pH 7.00 cradle.

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The complete question is:

A microbiologist is preparing a medium on which to culture E. coli bacteria. She buffers the medium at pH 7.00 to minimize the effect of acid-producing fermentation. What volumes of equimolar aqueous solutions of K_2HPO_4 and KH_2PO_4 must she combine to make 250.0 mL of the pH 7.00 buffer? K_a values for phosphoric acid: K_a_1 = 7.2 times 10^-3 K_a_2 = 6.3 times 10^-8 K_a_3 = 4.2 times 10^-13 Volume H_2PO_4^- = mL Volume HPO_4^2- = mL


Related Questions

if you are given three different capacitors C1, C2, and C3, how many different combiations of capacitance can you produce, using all capacitors in your circuits?

Answers

Assuming that the capacitors are distinct and not identical, there are eight possible combinations of capacitance that can be produced using all three capacitors in a circuit.

This is because each capacitor can either be included or excluded from the circuit, resulting in two possibilities for each capacitor. With three capacitors, there are 2x2x2 = 8 possible combinations.

For example, if C1 = 1μF, C2 = 2μF, and C3 = 3μF, the eight possible combinations would be 1μF, 2μF, 3μF, 1+2=3μF, 1+3=4μF, 2+3=5μF, 1+2+3=6μF, and no capacitor connected.

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How would the reading on a barometer change if you were to take one on a trip from los angeles to Lake Tahoe, which is at a much higher altitude?

Answers

The reading on a barometer would change if you were to take one on a trip from Los Angeles to Lake Tahoe, which is at a much higher altitude.


1. A barometer measures atmospheric pressure.
2. Atmospheric pressure decreases with an increase in altitude.
3. Los Angeles is at a lower altitude (approximately 305 feet or 93 meters above sea level) compared to Lake Tahoe (about 6,225 feet or 1,897 meters above sea level).
4. As you travel from Los Angeles to Lake Tahoe, the altitude increases.
5. Due to the increase in altitude, the atmospheric pressure decreases.
6. The barometer reading in Lake Tahoe will be lower than the reading in Los Angeles.

In conclusion, the barometer reading would be lower in Lake Tahoe compared to Los Angeles due to the higher altitude and the resulting decrease in atmospheric pressure.

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If you were to take a barometer on a trip from Los Angeles to Lake Tahoe, which is at a much higher altitude, the reading on the barometer would decrease as you ascend to higher altitudes.

A barometer is a device used to measure atmospheric pressure. The pressure at sea level is approximately 1013 hPa (hectopascals) or 29.92 inches of mercury (inHg). As you increase in altitude, the pressure decreases due to the decreased weight of the atmosphere above. For every 1000 feet increase in altitude, there is an approximate decrease of 1 inch of mercury (inHg) or 33 hPa in pressure.

Lake Tahoe has an elevation of approximately 6,225 feet, which is significantly higher than Los Angeles, which is only 233 feet above sea level. As a result, the atmospheric pressure at Lake Tahoe would be lower than the pressure in Los Angeles. Therefore, if you were to take a barometer from Los Angeles to Lake Tahoe, the reading on the barometer would decrease as you ascend to higher altitudes.

In summary, the reading on a barometer would decrease as you ascend to higher altitudes such as Lake Tahoe from Los Angeles.

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Electrochemistry-Related Question:




The answer is "A"

but I don't understand this question, I need explanation

Answers

The only incorrect statement in the diagram is (d) Cr202-7 can be used in aqueous H2SO4.

A detailed explanation of the Standard Electrode Potential

Option (d) is incorrect because the half-cell reaction involving Cr2O7^2- and H+ (aq) produces H2CrO4, which can decompose in acidic solutions, leading to inaccurate results. Therefore, Cr2O7^2- should not be used in aqueous H2SO4 for the quantitative estimation of Fe(NO3)2-.

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The Only incorrect statement is option C

What is electrochemistry?

Electrochemistry is a branch of chemistry that deals with the study of the relationship between electrical energy and chemical reactions.

It involves the study of the behavior of electrons and ions in chemical reactions that occur in a solution or at the interface between two different phases, such as a solid electrode and a liquid electrolyte.

We can see that it is better to use HCl instead of the use of the H2SO4 acid as we have in the options.

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what volume would be occupied by 100.0g of oxygen gas at a pressure of 1.5atm and a temperature of 25c?

Answers

100.0 g of oxygen gas at a pressure of 1.5 atm and a temperature of 25°C would occupy a volume of 49.2 L.

To solve this problem, we can use the Ideal Gas Law, which states:

PV = nRT

where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.

We need to rearrange this equation to solve for the volume V:

V = (nRT) / P

where n is the number of moles of the gas, which we can calculate using the molar mass of oxygen gas:

n = m / M

where m is the mass of the gas and M is the molar mass of oxygen gas (32 g/mol).

n = 100.0 g / 32 g/mol = 3.125 mol

Now we can substitute the given values into the equation to find the volume:

V = (nRT) / P

V = (3.125 mol)(0.0821 L·atm/mol·K)(298 K) / 1.5 atm

V = 49.2 L

Therefore, 100.0 g of oxygen gas at a pressure of 1.5 atm and a temperature of 25°C would occupy a volume of 49.2 L.

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Help what's the answer?

Answers

Answer:

91

Explanation:

ok

A mixture consisting of 1 mol of H2O(g) and
1 mol CO(g) is placed in a 14 L reaction vessel
at 800 K. At equilibrium, 0.42 mol CO2(g) is
present as a result of the reaction
CO(g) + H2O(g) ⇀↽ CO2(g) + H2(g).
What is Kc at 800 K?

Answers

The equilibrium constant (Kc) for the given reaction at 800 K is 1.

What is Equilibrium?

Chemical equilibrium is described by the equilibrium constant, which is a numerical value that quantitatively expresses the ratio of concentrations (or partial pressures) of reactants and products at equilibrium. The equilibrium constant is denoted by the symbol K, and its value depends on the specific chemical reaction and the temperature at which the reaction occurs.

According to the given information, at equilibrium, the concentration of C[tex]O_{2}[/tex] is 0.42 mol in a 14 L reaction vessel. Therefore, the equilibrium concentration of C[tex]O_{2}[/tex] ([C[tex]O_{2}[/tex]]) is 0.42 mol / 14 L = 0.03 mol/L.

The concentrations of CO ([CO]) and [tex]H_{2}O[/tex]([[tex]H_{2}O[/tex]]) at equilibrium can be calculated using the initial moles and the change in moles for each species. Since 1 mol of CO reacts with 1 mol of [tex]H_{2}O[/tex] to produce 1 mol of C[tex]O_{2}[/tex], the change in moles for CO and H2O is also 0.42 mol.

Equilibrium concentration of CO ([CO]) = Initial moles of CO - Change in moles of CO = 1 mol - 0.42 mol = 0.58 mol

Equilibrium concentration of [tex]H_{2}O[/tex] ([tex]H_{2}O[/tex]]) = Initial moles of [tex]H_{2}O[/tex] - Change in moles of [tex]H_{2}O[/tex] = 1 mol - 0.42 mol = 0.58 mol

Now, we can substitute these equilibrium concentrations into the equilibrium expression for Kc:

Kc = [C[tex]O_{2}[/tex]] / ([CO] * [[tex]H_{2}O[/tex]])

Plugging in the values:

Kc = (0.42)(0.42) / (0.42 * 0.42)

Kc = 1

So, the equilibrium constant (Kc) for the given reaction at 800 K is 1.

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at a certain temperature the solubility of lead(ii) iodide is 0.064 g/100 ml. what is the solubility product of lead(ii) iodide at this temperature? provide your answer rounded to 2 significant figures.

Answers

The solubility product (Ksp) of a substance is a measure of the maximum solubility of that substance in a given solution. It is calculated as the product of the molar concentrations of the ions present in the solution.

In the case of lead(II) iodide, the Ksp can be calculated as the product of the molar concentrations of Pb2+ and I− ions present in the solution.

At the given temperature, the solubility of lead(II) iodide is 0.064 /100 ml. Therefore, the molar concentrations of Pb2+ and I− ions in the solution would be 0.064/100 ml divided by the molar mass of lead(II) iodide (364/mol). This gives a Ksp of 4.07 x 10-9, which can be rounded to 4.1 x 10-9. This is the solubility product of lead(II) iodide at the given temperature.

In summary, the solubility product of lead(II) iodide at a certain temperature is 4.1 x 10-9 when rounded to two significant figures.

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What is the function of a buffer?

Answers

A buffer is a solution that can resist pH change upon the addition of an acidic or basic components. It is able to neutralize small amounts of added acid or base, thus maintaining the pH of the solution relatively stable. This is important for processes and/or reactions which require specific and stable pH ranges.

what is the most important use of an element's atomic number? what else can we know from a neutral atom's atomic number

Answers

The most important use of an element's atomic number is that it determines the identity of an element. From a neutral atom's atomic number, we can also determine the number of electrons in that atom.

The most important use of an element's atomic number is that it determines the element's unique identity and its position on the periodic table. The atomic number is equal to the number of protons in the nucleus of an atom, which also determines the number of electrons in a neutral atom.

From a neutral atom's atomic number, we can also determine the element's symbol, its electron configuration, and its properties such as its atomic mass and the number of isotopes it has. Additionally, the atomic number can provide information about the element's reactivity and its ability to bond with other elements to form compounds. Overall, the atomic number is a fundamental characteristic of an element that is used in many different areas of chemistry and physics.

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The most important use of an element's atomic number is that it determines the element's unique identity and properties.

The atomic number also tells us the number of protons in the nucleus of an atom, which in turn determines the number of electrons in the neutral atom. Additionally, the atomic number can give us information about the element's electron configuration and its position on the periodic table. Overall, the atomic number is a crucial piece of information for understanding an element's properties and behavior.
Hi! The most important use of an element's atomic number is to identify the specific element and its position in the periodic table. The atomic number represents the number of protons in the nucleus of an atom of that element.

From a neutral atom's atomic number, we can also determine the number of electrons, as a neutral atom has an equal number of protons and electrons. This information helps us understand the element's chemical properties and reactivity, as the arrangement of electrons in the atom's electron shells influences its behavior in chemical reactions.

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Observations CuSO4 & NH4Cl Conventional, total ionic, net ionic

Answers

Therefore, the net ionic equation for the reaction is Copper(2+) (aq) + 2 chlorine- (aq) → Copper(II) chloride (aq).

What takes place when Copper(II) sulfate and Ammonium hydroxide interact?

Ammonium sulphate and Copper hydroxide precipitate are the first products of the reaction between copper sulphate and ammonium hydroxide.

Mixing copper(II) sulphate and ammonium chloride results in the following observations:

Conventional: When copper ions (Copper2+) from Copper(II) sulfate are present, a blue solution develops. The colour of Ammonium Chloride doesn't seem to have changed at all.

Ionic total: While Ammonium Chloride dissociates into Ammonium and Chlorine- ions in solution, Copper(II) sulfate dissociates into Copper2+ and Sulfate 2- ions.

Copper(II) sulfate (aq) + 2 Ammonium Chloride (aq) → Copper(II) Chloride (aq) + 2 Ammonium (aq) + Sulfate 2- (aq)

Net Ionic: The net ionic equation shows only the species involved in the reaction. In this case, the Copper2+ and the Cl- ions combine to form Copper(II) chloride.

Copper2+ (aq) + 2 Chlorine- (aq) → Copper(II) chloride (aq)

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13.8 g of neon gas is placed in a container at 34 oc and 812 mm hg. what is the volume of the container (in l)?

Answers

The volume of the container is 16.9 L.To find the volume of the container, we can use the ideal gas law: PV = nRT

where P is the pressure in atmospheres (convert 812 mmHg to atm), V is the volume in liters (what we're solving for), n is the number of moles of gas (we're given 13.8 g of neon, which we can convert to moles using the atomic weight), R is the gas constant (0.0821 L·atm/mol·K), and T is the temperature in Kelvin (convert 34°C to K).

First, let's convert the pressure:

812 mmHg = 1.068 atm

Next, let's convert the temperature:

34°C = 307 K

Now, let's convert the mass of neon to moles:

13.8 g / 20.18 g/mol = 0.683 mol

Now we can plug in all the values and solve for V:

V = (nRT) / P
V = (0.683 mol x 0.0821 L·atm/mol·K x 307 K) / 1.068 atm
V = 16.9 L

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How much energy is radiated by a non-spinning black hole that accretes 10-7 Msun per year? We compute this using L=ηMc2 (where M is the accretion rate). Putting in the numbers, we find L=0.06(10-7 x 6.3 kg/s)(3 x 108 m/s)2 = 3.4 x 1031.

Answers

The energy radiated by the black hole would be approximately 3.4 x 1031 Joules per second.This means the black hole radiates 3.4 x 10^31 watts of energy.

The energy radiated by a non-spinning black hole that accretes 10-7 Msun per year can be computed using the formula L=ηMc2, where M is the accretion rate. Putting in the numbers, we find L=0.06(10-7 x 6.3 kg/s)(3 x 108 m/s)2 = 3.4 x 1031. Therefore, the energy radiated by the black hole would be approximately 3.4 x 1031 Joules per second.

To calculate the energy radiated by a non-spinning black hole that accretes 10^-7 Msun per year, you can use the formula L=ηMc^2, where L is the luminosity, η is the efficiency, M is the accretion rate, and c is the speed of light. Plugging in the numbers, L=0.06(10^-7 x 6.3 kg/s)(3 x 10^8 m/s)^2 = 3.4 x 10^31. This means the black hole radiates 3.4 x 10^31 watts of energy.

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The breakdown of a certain pollutant X in sunlight is known to follow first-order kinetics. An atmospheric scientist studying the process fills a 20. 0Lreaction flask with a sample of urban air and finds that the partial pressure of X in the flask decreases from 0. 473atm to 0. 376atm over 5. 6hours.


Calculate the initial rate of decomposition of X, that is, the rate at which Xwas disappearing at the start of the experiment.


Round your answer to 2 significant digits

Answers

The initial rate of decomposition of X is 0.0013 M/h.

The first-order rate law is given as:

Rate = k [X]

Where, k = rate constant

[X] = concentration of X

Since the partial pressure of X is given in the problem, we need to convert it to concentration using the ideal gas law:

PV = nRT

where:

P = partial pressure of X = 0.473 atm

V = volume of the flask = 20.0 L

n = number of moles of X

R = ideal gas constant = 0.08206 L atm K^-1 mol^-1

T = temperature of the flask (assumed constant) = 298 K

Solving for n,

n = PV/RT = (0.473 atm)(20.0 L)/(0.08206 L atm K^-1 mol^-1)(298 K) = 0.952 mol X

At t = 0, the concentration of X is [X]_0 = n/V = 0.952 mol/20.0 L = 0.0476 M.

Using the given data, we can calculate the rate constant (k) as follows:

ln([X]_0/[X]) = kt

where:

t = time = 5.6 hours

Substituting the given values,

ln(0.0476/0.0376) = k(5.6 hours)

Solving for k, we get:

k = (ln(0.0476/0.0376))/5.6 hours = 0.0263 h^-1

The initial rate of decomposition of X is given by:

Rate = k[X]_0 = (0.0263 h^-1)(0.0476 M) = 0.00125 M/h

Rounding off to 2 significant digits,

Initial rate of decomposition of X = 0.0013 M/h.

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ما
1. Blood plasma contains a total carbonate pool of 0. 0252M.
(a) What is the HCO3"/CO2 ratio
(b) What is the concentration of each buffer component present at pH=7. 4
(c) What would the pH be if 0. 01M H" is added assuming that the excess CO2 is not
released.
(d) What would the pH be if 0. 01M H is added assuming that the excess CO2 is released. ​

Answers

(a) The HCO₃⁻ / CO₂ ratio is 20 : 1.

(b) The concentration of each buffer  present at the pH=7. 4 is [CO₂] = 1.20 × 10⁻³ M, [HCO₃⁻] = 0.0240 M.

(c) The pH be if 0. 01M H⁺ is added ,the excess CO2 is not released is 6.20.

(d) The pH be if 0. 01M H⁺ is added , the excess CO2 is released. is 7.17.​

(a) pH = pka + log HCO₃ / CO₂

HCO₃⁻ / CO₂ = 10^pH - pka

HCO₃⁻ / CO₂ = 10 ^7.4 - 6.1

HCO₃⁻ / CO₂ = 20 : 1

(b) Total concentration = 0.0252 M

HCO₃⁻ + CO₂ = 0.0252

20 CO₂ + CO₂ = 0.0252

[CO₂] = 1.20 × 10⁻³ M

[HCO₃⁻ ] = 0.0240 M

(c) pH = pka + log HCO₃ / CO₂

pH = 6.1 + log 0.0140 / 0.0112

pH = 6.20

(d) pH = pka + log HCO₃ / CO₂

pH = 6.1 + log 0.0140 / 1.20 × 10⁻³

pH = 7.17

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1. Create a diagram of your electroplating apparatus (an electrolytic cell). Then submit your drawing with the following terms labeled correctly. Or, beginning with the positive terminal of the battery and ending with the negative terminal of the battery, describe the path that the electricity takes and where each of the following occurs:
anode
cathode
copper strip
battery
positive terminal
negative terminal
place where oxidation occurs
place where reduction occurs
electrolyte solution
coin (or nail)
direction of electron flow

2. Write the two half-reactions that occur in this electroplating process. Be sure to include the states of the elements or ions.

Answers

The two half-reactions that occur in this electroplating process are oxidation and reduction. the diagram is attached

What is oxidation?

Oxidation is a chemical reaction in which an atom or molecule either loses or gains electrons. This process results in the oxidation of the atom or molecule, leading to a chemical change in the molecule. Oxidation occurs when electrons are removed from the molecule, causing it to become more positively charged. This can lead to the formation of new molecules, such as oxygen (O₂) and carbon dioxide (CO₂).

Oxidation occurs at the anode, where electrons are released from the copper strip and it is oxidized to form copper ions (Cu²⁺). The copper ions are then dissolved into the electrolyte solution. Reduction occurs at the cathode, where the copper ions in the electrolyte solution are reduced using electrons from the battery and deposited onto the coin (or nail). The direction of electron flow is from the positive terminal of the battery, to the anode, to the electrolyte solution, to the cathode, and finally to the negative terminal of the battery.

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which means of actuation for a co2 system is triggered by a product-of-combustion detector in the co2 system?

Answers

The actuation method triggered by a product-of-combustion detector in a CO2 system is typically referred to as "automatic actuation."

In this method, the product-of-combustion detector senses the presence of a fire or heat source and sends a signal to the CO2 system, causing it to automatically release CO2 to extinguish the fire.

This actuation method is commonly used in areas where fires may start unexpectedly, such as in server rooms, electrical substations, and other critical infrastructure facilities. It provides a fast and effective response to fires, helping to minimize damage and protect personnel.

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Scenario - Read the experimental design scenario and complete the IVCDV.
Adam wanted to see if he would get better at an exercise if he repeated the exercise over time. To test
this, he got a clothes pin and opened it and closed it as many times as he could in 60 seconds using only
his thumb and forefinger. He rested for one minute. Then, he did the same thing again. He opened and
closed the clothes pin as many times as he could for 1 minute. He kept doing this until he completed 10
trials with 1 minute rest time in between each trial. If the number of times he opened and closed the
close pin increased, then he got better at the exercise during this 20 minute experiment. If the number of
times he opened and closed the close pin decreased, then he did not get better at the exercise during this
20 minute experiment.

Answers

The repetition of the exercise over time is the IV (independent variable) in this example of an experimental design.

What is exercise?

Exercise is physical activity that is done to maintain or improve one's physical health and fitness. It usually entails exercises like jogging, running, cycling, swimming, weightlifting, or taking part in sports.

Adam is experimenting with the IV to see whether it has an impact on the DV (dependent variable), which is the number of times he can open and shut the clothes pin using only his thumb and forefinger in 60 seconds, by doing the exercise several times. Adam is checking the DV to determine whether there has been a change as a result of the IV.

Adam has regulated various factors to guarantee that the outcomes are trustworthy. For each experiment, he is, for instance, using the same clothes pin, opening and closing it with the same fingers, and timing each trial for exactly 60 seconds. In order to prevent weariness from impairing his performance, Adam is also taking a one-minute break between each session.

The idea is that if Adam performs the exercise repeatedly over time, he will get more adept at it. This theory is predicated on the idea that repetition and practice can enhance a person's capacity to carry out a physical job.

Adam will compare how many times he opened and closed the clothes pin in each trial, starting with the first, to determine the outcomes. The increase in the number indicates that Adam becomes more adept at the practice. If the number falls or stays the same, the hypothesis is refuted, then it may be said that repetition had no positive effect on performance.

Overall, this scenario for an experimental design provides a straightforward yet efficient approach to evaluate the claim that doing a physical activity repeatedly will increase performance. It highlights the significance of limiting variables and calculating the DV to get relevant results.

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a 88.06 g sample of calcium hydroxide is dissolved in enough water to make 1.520 liters of solution. calculate the volume in ml of this solution that must be diluted with water in order to make 2.100 l of 0.250 m calcium hydroxide. what is the coefficient of your answer in scientific notation?

Answers

First, let's calculate the number of moles of calcium hydroxide in the initial solution:

88.06 g Ca(OH)2 = 88.06/74.093 g/mol = 1.188 mol Ca(OH)2
To make 2.100 L of 0.250 M solution, we need:

2.100 L x 0.250 mol/L = 0.525 mol Ca(OH)2
Let's call the volume of the initial solution that we need to dilute "V":

V x (1.188 mol/1.520 L) = 0.525 mol/2.100 L
Solving for V, we get:

V = (0.525 mol/2.100 L) x (1.520 L/1.188 mol) = 0.336 L = 336 mL
The coefficient of this answer in scientific notation is 3.36 x 10^2.

Question 5
Which of the following plants is known for its ability to absorb nitrates in polluted
water?
O cat tails
Oferns
O water lilies
O kelp

Answers

The sweet fiber in cat tail roots provides an abundance of starchy carbohydrates. The common cattail is not a perfect flower. Among the given options, cat tails  absorb nitrates from polluted water. The correct option is A.

The cattail flower spikes can be possible to boil and can be eaten just like the corn on the cob. Pollen from the matured flowers can be collected and can be used with other flour to make biscuits, muffins and pancakes.

Cattails have an amazing ability to absorb phosphorous, nitrogen and other elements which can destruct the water bodies and sediment beds. They play a vital function in treating wastewater.

Thus the correct option is A.

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the structures of d-gulose and d-psicose are shown above. what test could be used to distinguish between solutions of these two carbohydrates? explain your answer by predicting the results of the test for each sugar.

Answers

a small amount of Tollens' reagent (ammoniacal silver nitrate) is added to the sugar solution and the mixture is heated. If a reducing sugar is present, it will reduce the silver ions in the Tollens' reagent to metallic silver, which will form a silver mirror on the inside of the test tube.

Based on the structures of D-gulose and D-psicose, it can be predicted that both sugars will give a positive result in the Tollens' test because they both have an aldehyde group that can act as a reducing agent. However, the intensity of the reaction may differ for each sugar.

D-gulose has an aldehyde group at carbon 1, which is in the linear form of the sugar, while D-psicose has an aldehyde group at carbon 2. Since D-gulose can easily convert to its linear form, it is expected to give a stronger positive result in the Tollens' test compared to D-psicose, which may show a weaker positive result due to the steric hindrance of the bulky ketone group at carbon 3.

In summary, the Tollens' test can be used to distinguish between solutions of D-gulose and D-psicose by observing the intensity of the silver mirror formed. D-gulose is expected to give a stronger positive result due to its ability to convert to the linear form, while D-psicose may show a weaker positive result due to steric hindrance.

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During chemistry class, Carl performed several lab test on two white solids. The results of three tests are seen in the data table. Based on this data, Carl has concluded that substance B must have ______ bonds.

Answers

Carl has concluded that substance have ionic bonds.

How can you tell whether or not a covalent bond is polar?

The usual guideline is that a bond is considered nonpolar if the difference in electronegativities is less than or equal to 0.4, while there are no hard and fast rules, and polar if the difference is greater.

What sort of covalent bond has a non-polar example?

The bond between two hydrogen atoms is an illustration of a nonpolar covalent bond since they equally share electrons. The bond between two chlorine atoms is another illustration of a nonpolar covalent bond since they also equally share electrons.

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Question:

During che distry class, Cort performed several lab tests on two white solids. The results of three tests are seen in the data table. Based on this data, Carl has concluded that substance have ________ bonds.

A) covalent

B) diatomic

C) ionic

D) metallic

which of the following donates electrons to free radicals in order to neutralize them? group of answer choices superoxide dismutase catalase glutathione peroxidase vitamin e

Answers

The correct answer is option D. Vitamin E is an antioxidant that helps to neutralize free radicals by donating electrons.

By reacting with reactive oxygen species, it breaks the chain of oxidative reactions by generating a stable end product.

It aids in preventing oxidative cell damage, which can result in illnesses like cancer. It has been demonstrated that vitamin E lowers the risk of heart disease and aids in the reduction of inflammation.

It has also been connected to better brain health because it has been demonstrated to fend off age-related cognitive decline.

Numerous foods, such as nuts, seeds, and vegetable oils, as well as supplements, contain vitamin E.

Complete Question:

Which of the following helps to neutralize free radicals by donating electrons?

Group of answer choices

A. Superoxide Dismutase

B. Catalase

C. Glutathione Peroxidase

D. Vitamin E

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which of the following phase changes is exergonic? question 29 options: melting vaporization all phase changes are exergonic condensation

Answers

Only  the condensation is an exergonic phase change.

Exergonic refers to a process that releases energy. Among the given options, the exergonic phase change is condensation. When a gas turns into a liquid during condensation,

it releases heat energy. This is because the molecules lose kinetic energy and move closer together, forming stronger attractive forces. The energy that was previously used to keep the gas molecules apart is released as heat energy.

On the other hand, melting and vaporization are endergonic phase changes, which require an input of energy to occur. Melting requires heat energy to break the intermolecular bonds between the solid molecules,

while vaporization requires even more energy to overcome the stronger intermolecular forces in the liquid and form a gas.

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calculate the mass of solid agcl that is produced when 525ml of .35 m alcl3 is used with excess ag2so4 solution

Answers

The mass of solid AgCl produced when 525 mL of 0.35 M AlCl3 is used with excess Ag2SO4 solution is 78.97 g.

The balanced chemical equation for the reaction between AlCl3 and Ag2SO4 is:

2 AlCl3 + 3 Ag2SO4 → Al2(SO4)3 + 6 AgCl

From the equation, we can see that 2 moles of AlCl3 react with 3 moles of Ag2SO4 to produce 6 moles of AgCl. Therefore, the mole ratio of AlCl3 to AgCl is 2:6 or 1:3.

To calculate the moles of AgCl produced, we need to first calculate the moles of AlCl3 used.

Moles of AlCl3 = concentration x volume / 1000

Moles of AlCl3 = 0.35 mol/L x 0.525 L

Moles of AlCl3 = 0.18375 mol

Since the mole ratio of AlCl3 to AgCl is 1:3, the moles of AgCl produced is:

Moles of AgCl = 3 x Moles of AlCl3

Moles of AgCl = 3 x 0.18375 mol

Moles of AgCl = 0.55125 mol

The molar mass of AgCl is 143.32 g/mol. Therefore, the mass of AgCl produced is:

Mass of AgCl = moles of AgCl x molar mass of AgCl

Mass of AgCl = 0.55125 mol x 143.32 g/mol

Mass of AgCl = 78.97 g

Therefore, the mass of solid AgCl produced when 525 mL of 0.35 M AlCl3 is used with excess Ag2SO4 solution is 78.97 g.

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a buffer is prepared by adding 1.00 l of 1.0 m hcl to 750 ml of 1.5 m nahcoo. what is the ph of this buffer? [ka (hcooh)

Answers

Answer:The pH of a buffer prepared by adding 1.00 L of 1.0 M HCl to 750 ml of 1.5 M NaHCOO is 2.84

What is pH?

pH is a measure of the acidity of a solution.

pH is calculated from the negative logarithm to base ten of the hydrogen ions concentration of the solution.

For weak acids such as those used in the preparation of buffers, the acid dissociation constant, Ka are used to determine the pH of the solution.

Therefore, from the Ka of acetic acid, the pH of a buffer prepared by adding 1.00 L of 1.0 M HCl to 750 ml of 1.5 M NaHCOO is 2.84

Solid sodium chloride decomposes into chlorine gas and solid sodium .
what is the balanced chemical equation of this please help im stuck thanks

Answers

2NaCl --> 2Na + Cl2 but I have never seen something this reaction happening

which compounds used in this experiment should one be careful with when using a hot plate? 4-methylphenol and diethyl ether 2-methyl-2-propanol and sulfuric acid diethyl ether and tert-butanol 4-methylphenol and glacial acetic acid

Answers

One should be careful with diethyl ether and tert-butanol when using a hot plate as they have low flash points and can easily ignite.

It is important to take proper precautions such as using a well-ventilated area and avoiding any sources of ignition. Sulfuric acid and glacial acetic acid are also potentially dangerous as they are corrosive and can cause severe burns if they come into contact with skin. Propanol and butanol have higher flash points and are generally safer to use on a hot plate.


When using a hot plate in an experiment, one should be particularly careful with diethyl ether and tert-butanol. Diethyl ether is highly flammable and volatile, while tert-butanol (2-methyl-2-propanol) can generate flammable vapors when heated. These compounds pose a risk of fire or explosion if not handled properly.

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how many moles of aluminum nitrate are obtained from the reaction of 0.75 mol of silver nitrate with a sufficient amount of aluminum?

Answers

The balanced chemical equation for the reaction between aluminum and silver nitrate is:

2 Al + 3 AgNO3 → 3 Ag + 2 Al(NO3)3

From the equation, we can see that 3 moles of aluminum nitrate (Al(NO3)3) are produced for every 3 moles of silver nitrate (AgNO3) consumed.

Therefore, if 0.75 moles of silver nitrate react, we can calculate the number of moles of aluminum nitrate produced as follows:

0.75 mol AgNO3 x (2 mol Al(NO3)3 / 3 mol AgNO3) = 0.50 mol Al(NO3)3

So, 0.50 moles of aluminum nitrate (Al(NO3)3) are obtained from the reaction of 0.75 mol of silver nitrate with a sufficient amount of aluminum.

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if a solution originally 0.532 m in acid ha is found to have a hydronium concentration of 0.112 m at equilibrium, what is the percent ionization of the acid?

Answers

To find the percent ionization of the acid, we need to first calculate the initial concentration of the acid (HA) before it dissociates.

Since the solution is originally 0.532 M in acid (HA), we can assume that the initial concentration of HA is also 0.532 M.

Next, we need to calculate the concentration of the conjugate base (A-) at equilibrium. We can use the equation for the dissociation of an acid:
HA + H2O ⇌ H3O+ + A-

We know that the hydronium concentration at equilibrium is 0.112 M, so the concentration of the conjugate base is also 0.112 M.

To calculate the percent ionization of the acid, we use the equation:
% ionization = (concentration of dissociated acid / initial concentration of acid) x 100

We can find the concentration of dissociated acid (H3O+) by subtracting the concentration of the conjugate base (A-) from the hydronium concentration:


[H3O+] = 0.112 M - 0 M = 0.112 M

Plugging in the values, we get:
% ionization = (0.112 M / 0.532 M) x 100 = 21.05%

Therefore, the percent ionization of the acid is 21.05%.

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The percent of ionization of an acid in solution of 0.532 M in acid HA i and have a hydronium concentration of 0.112 M is equals to the 21.1%.

The ionization of acids results hydrogen ions, thus, that's why compounds act as proton donors.

Molarity of solution = 0.532 M

At Equilibrium, hydronium concentration = 0.112 M

As we know, concentration is defined as the number of moles of substance in a litre of solution, that most of time concentration is replaced by molarity. So, concentration of acid solution, [ H A] = 0.532 M

Chemical reaction, [tex]HA (aq) + H_2O -> H_3O^{ +}+A^{-}[/tex]

percent of ionization of the acid =

[tex] \frac{ [ H_3O^{+}] }{ [ HA]} × 100 [/tex]

= (0.112/0.532) × 100

= 21.1%

Hence, required value is 21.1%.

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Read the given chemical reaction.


C2H6 + O2 → CO2 + H2O


How many moles of O2 are required to react completely with 3. 2 moles of C2H6?


3. 5 moles of O2

6. 5 moles of O2

10. 4 moles of O2

11. 2 moles of O2

Answers

11.2 moles of [tex]\rm O_2[/tex] are required to react completely with 3.2 moles of [tex]\rm C_2H_6[/tex]. Therefore option D is correct.

The balanced chemical equation for the complete combustion of [tex]\rm C_2H_6[/tex] (ethane) with oxygen (O2) is: 2 [tex]\rm C_2H_6 + 7 O_2\ - > 4 CO_2 + 6 H_2O[/tex]

From the balanced equation, we can see that 2 moles of [tex]\rm C_2H_6[/tex] react with 7 moles of [tex]\rm O_2[/tex]. To find out how many moles of [tex]\rm O_2[/tex] are required to react completely with 3.2 moles of [tex]\rm C_2H_6[/tex], we can set up a proportion:

(7 moles [tex]\rm O_2[/tex] / 2 moles [tex]\rm C_2H_6[/tex]) = (x moles [tex]\rm O_2[/tex] / 3.2 moles [tex]\rm C_2H_6[/tex])

Solving for x:

x = (7 moles [tex]\rm O_2[/tex] / 2 moles [tex]\rm C_2H_6[/tex]) * 3.2 moles [tex]\rm C_2H_6[/tex]

x = 11.2 moles [tex]\rm O_2[/tex]

So, 11.2 moles of [tex]\rm O_2[/tex] are required to react completely with 3.2 moles of [tex]\rm C_2H_6[/tex]. Therefore, the correct answer is 11.2 moles of [tex]\rm O_2[/tex].

Therefore option D is correct.

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