Answer:
[H⁺] = 0.01 M[OH⁻] = 1x10⁻¹² MpH = 2Explanation:
The assumption that the HCl is completely ionized means that the original concentration of the acid is equal to [H⁺].
[H⁺] = 0.01 MWith [H⁺], we can calculate [OH⁻], by using the following formula:
[H⁺] * [OH⁻] = 10⁻¹⁴0.01 M * [OH⁻] = 10⁻¹⁴[OH⁻] = 1x10⁻¹² MFinally we calculate the pH of the solution:
pH = -log[H⁺]pH = 2There are four stages to the classical demographic transition model Pre-transitional Europe was characterized by high and
fluctuating mortality and a high birth rate. The transition model began to progress into and through stage 2 in the late 18th and early
19th century. All BUT ONE contributed to the decline in mortality.
S- -1]))
A)
Enacting measures to provide clean water supplies.
B)
Public health advances including quarantine of settlements undergoing
epidemics
The development of vaccines to prevent disease and antibiotics to treat
infection.
D)
Widespread acceptance of germ theory resulting in more hygienic
practices, including hand washing and sterilizing medical equipment and
infants' bottles.
Question 6 (4 points)
(08.02 MC)
What is the percentage by mass of solution formed by dissolving 27.0 grams of HCl in 102.0 grams of water? (4 points)
а
26.596
D
20.946
с
18.296
d
16.796
Answer:
20.9%
Explanation:
I took the test i hope this helps:)
The percentage by mass of solution formed by dissolving 27.0 grams of HCl in 102.0 grams of water is 20.93%. This is calculated using the definition (formula) of percentage by mass of a solution.
What is meant by percentage by mass?The mass percent of a solution is defined as the ratio of the mass of solute that is present in a solution, relative to the mass of the solution, as a whole.
The formula for percentage by mass is given as
percentage by mass = (mass of the solute/ total mass of the compound solution) × 100
Calculating percentage by mass for the given solution:The mass of the solute ( the chemical which is going to be dissolved) HCl
= 27.0 grams
The mass of the solvent (the substance in which a solute dissolve) water
= 102.0 grams
So, the total mass of the solution = 27.0 + 102.0 = 129.0 grams
Then, the percentage by mass = [tex]\frac{27.0}{129.0}[/tex] × 100 = 20.93%
Which is approximate equal to 20.946 at option B.
Therefore, the percentage by mass of solution formed by dissolving 27.0 grams of HCl in 102.0 grams of water is 20.93%.
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differences between diamond and graphite
Answer:
dimond is stronger
Explanation:
Answer:
Graphite and Diamond are different because they have different structures. ... However each carbon atom in Diamond has 4 covalent bonds with other Carbons, making it extremely strong and hard. On the other hand, each carbon in graphite is bonded to three carbons, and therefore graphite is formed in layer
Also:
Each carbon atom in a diamond is linked to four other carbon atoms. Each carbon atom in graphite is linked to three other carbon atoms. Diamond is poor conductor of electricity due to the absence of free electrons. Graphite is good conductor of electricity due to the presence of free electrons in its structure.
Explanation:
Hope this helps
The molar mass of water is 18.02 g/mol. A mass of 160.0 grams of water is equivalent to how many moles?
please show work!
Answer:
8.879 moles.
Explanation:
From the question given above, the following data were obtained:
Molar mass of water = 18.02 g/mol
Mass of water = 160.0 g
Mole of water =?
Mole is defined by the following equation:
Mole = mass / molar mass
With the above formula, we can obtain the number of mole present in 160 g of water. This can be obtained as follow:
Molar mass of water = 18.02 g/mol
Mass of water = 160.0 g
Mole of water =?
Mole = mass / molar mass
Mole of water = 160 / 18.02
Mole of water = 8.879 moles.
Therefore, 160 g of water contains 8.879 moles.
0.850 moles of N2 originally at 85°C is cooled such that it now occupies 17.55L at 1.25 atm. What is the final temperature of the gas?
The final temperature of the gas is 269.9 K, or -3.25 °C, which was calculated with the help of ideal gas equation.
What is the ideal gas equation?The ideal gas equation gives the relation between pressure, volume and temperature.
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 in Kelvin.
To find the initial volume of the gas. We can use the fact that the number of moles of gas does not change during the cooling process:
n = 0.850 moles
We can also use the ideal gas law to find the initial volume of the gas:
PV = nRT
V = nRT/P
where R = 0.08206 L atm/K mol is the gas constant.
Convert the initial temperature from Celsius to Kelvin:
T1 = 85 °C + 273.15 = 358.15 K
Substitute the given values into the equation:
V₁ = (0.850 mol)(0.08206 L atm/K mol)(358.15 K)/(1 atm) = 24.03 L
Now we can use the combined gas law to find the final temperature:
(P₁V₁/T₁) = (P₂V₂/T₂)
Substitute the given values into the equation:
(1.25 atm)(24.03 L)/(358.15 K) = (P₂) (17.55 L)/(T2)
Solve for T₂:
T₂ = (P₂)(17.55 L)(358.15 K)/(1.25 atm)(24.03 L)
T₂ = 269.9 K
Therefore, the final temperature of the gas is 269.9 K, or -3.25 °C.
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how many molecules in 400g of acetic acid
Answer:chemical formula of acetic acid is or
so, molecular mass of acetic acid = 2 × atomic mass of C + 4 × atomic mass of H + 2 × atomic mass of O
= 2 × 12 + 4 × 1 + 2 × 16
= 24 + 4 + 32
= 60g/mol
given mass of acetic acid = 22g
so, no of moles of acetic acid = given mass/molecular mass
= 22/60 ≈ 0.367
so, number of moles of acetic acid is 0.367mol
number of molecules in 0.367 mol of acetic acid = 6.022 × 10²³ × 0.367
= 2.21 × 10²³
Explanation:
1. How does a virus differ from a common cell?
A. It has no nucleus, cell wall, or organelles.
B. It has two nuclei and no cell wall or organelles.
C. A virus has no cell well, no nucleus, and only organelles for
movement.
D. A virus differs from a cell only in shape.
A certain mass of water was heated with 41,840 Joules, raising its temperature from 22.0°C to 28.5 °C. Find the
mass of the water.
Answer:
1.5 × 10³ g
Explanation:
Step 1: Given and required data
Transferred heat (Q): 41,840 JInitial temperature: 22.0 °CFinal temperature: 28.5 °CSpecific heat capacity of water (c): 4.184 J/g.°CStep 2: Calculate the temperature change
ΔT = 28.5°C - 22.0 °C = 6.5 °C
Step 3: Calculate the mass (m) of water
We will use the following expression.
Q = c × m × ΔT
m = Q / c × ΔT
m = 41,840 J / (4.184 J/g.°C) × 6.5 °C = 1.5 × 10³ g
Inquiry Extension Consider a reaction that occurs between solid potassium and chlorine gas. If you start with an initial mass of 15.20 g K, and an initial mass of 2.830 g Cl2, calculate which reactant is limiting. Explain how to determine how much more of the limiting reactant would be needed to completely consume the excess reactant. Verify your explanation with an example
The 3.13 g of K would be needed to completely react with the remaining [tex]Cl_2[/tex].
To determine which reactant is limiting, we need to calculate the amount of product that can be formed from each reactant and compare them. The reactant that produces less product is the limiting reactant, since the reaction cannot proceed further once it is consumed.
The balanced chemical equation for the reaction between solid potassium and chlorine gas is:
2 K(s) + [tex]Cl_2[/tex](g) -> 2 KCl(s)
From the equation, we can see that 2 moles of K react with 1 mole of [tex]Cl_2[/tex] to form 2 moles of KCl.
First, we need to convert the masses of K and [tex]Cl_2[/tex] into moles:
moles of K = 15.20 g / 39.10 g/mol = 0.388 mol
moles of [tex]Cl_2[/tex] = 2.830 g / 70.90 g/mol = 0.040 mol
Now, we can use the mole ratio from the balanced equation to calculate the theoretical yield of KCl from each reactant:
Theoretical yield of KCl from K: 0.388 mol K x (2 mol KCl / 2 mol K) = 0.388 mol KCl
Theoretical yield of KCl from [tex]Cl_2[/tex]: 0.040 mol [tex]Cl_2[/tex] x (2 mol KCl / 1 mol [tex]Cl_2[/tex]) = 0.080 mol KCl
We can see that the theoretical yield of KCl from K is 0.388 mol, while the theoretical yield of KCl from [tex]Cl_2[/tex] is 0.080 mol. Therefore, the limiting reactant is [tex]Cl_2[/tex], since it produces less product.
To determine how much more of the limiting reactant would be needed to completely consume the excess reactant, we can use the stoichiometry of the balanced equation.
We know that 1 mole of [tex]Cl_2[/tex] reacts with 2 moles of K to produce 2 moles of KCl. Therefore, the amount of additional K needed to react with the remaining [tex]Cl_2[/tex] can be calculated as follows:
moles of K needed = 0.040 mol [tex]Cl_2[/tex] x (2 mol K / 1 mol [tex]Cl_2[/tex])
= 0.080 mol K
This means that 0.080 moles of K would be needed to completely consume the remaining [tex]Cl_2[/tex]. We can convert this to a mass by multiplying by the molar mass of K:
mass of K needed = 0.080 mol K x 39.10 g/mol
= 3.13 g K
Therefore, The 3.13 g of K would be needed to completely react with the remaining.
Example verification:
Suppose we had an additional 0.50 g of [tex]Cl_2[/tex] in the reaction. Would all of the K be consumed, or would there still be excess K?
Moles of additional [tex]Cl_2[/tex] = mass of [tex]Cl_2[/tex] / molar mass of [tex]Cl_2[/tex]
Moles of additional [tex]Cl_2[/tex] = 0.50 g / 70.90 g/mol
Moles of additional [tex]Cl_2[/tex] = 0.0070 mol
The theoretical yield of KCl that can be formed from the additional [tex]Cl_2[/tex] is:
0.0070 mol [tex]Cl_2[/tex] x (2 mol KCl / 1 mol [tex]Cl_2[/tex]) x (74.55 g KCl / 1 mol KCl) = 1.04 g KCl
Therefore, the total amount of KCl that can be formed from all of the [tex]Cl_2[/tex] is:
5.95 g + 1.04 g = 6.99 g
The amount of K that would be needed to completely consume all of the [tex]Cl_2[/tex].
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Cell membranes are selectively permeable. This means that A. only water can move freely across the cell membrane. B. any substance can move across the cell membrane, but chemical energy will always be required. C. some substances can move freely across the cell membrane, while others must be transported. D. no substances can move freely across the cell membrane.
Answer:
C. some substances can move freely across the cell membrane, while others must be transported.
Explanation:
PLEASE HELP I HAVE 19 MINUTES LEFT I WILL MARK BRAINLIEST
How much more acidic is a pH of 4 as compared to a pH of 6.5?
Answer:
316.227766
Explanation:
A balloon is inflated to a volume of 8.0 L on a day when the atmospheric pressure is 1.013 bar . The next day, a storm front arrives, and the atmospheric pressure drops to 0.968 bar . Assuming the temperature remains constant, what is the new volume of the balloon, in liters
Answer:
[tex]V_2=8.4L[/tex]
Explanation:
Hello there!
In this case, according to the definition of the Boyle's law, which describes de pressure-volume behavior as an inversely proportional relationship, it is possible for us to write:
[tex]P_1V_1=P_2V_2[/tex]
Thus, since we are given the initial pressure and temperature, and the final pressure, we are able to calculate the final volume as shown below:
[tex]baV_2=\frac{P_1V_1}{P_2}\\\\V_2=\frac{8.0L*1.013bar}{ 0.968bar}\\\\V_2=8.4L[/tex]
Regards!
How can heat energy transform from mechanical energy?
A)Burning
B)Friction
C)Light
D)Flames
Answer:
A
Explanation:
brainliest pls
Which organic compound listed below does not have a carbonyl group ?
A. Aldehyde
B. Ketone
C. Ethers
D. Protein
E. Ester
F. Amides
write half-reactions that show how H2O2 can act as either an oxidizing agent or a reducing agent, and describe where each of these situations occurred in your testing.
Answer:
H2O2 reduces itself to H2O and also oxidizes to O2 simultaneously thereby acting both as an oxidizing and reducing agent .
Explanation:
When
H2O2 acts as an oxidizing agent
H2O2 + 2e- 2H+---> 2H2O
Reducing agent
H2O2 --> O2 + 2e + 2H+
H2O2 reduces itself to H2O and also oxidizes to O2 simultaneously thereby acting both as an oxidizing and reducing agent .
A student pours 10.0 g of salt into a container of water and observes the amount of time it takes for the salt to dissolve. She then repeats the process using the same amounts of salt and water but this time she slowly stirs the mixture while it is dissolving. The student performs the experiment one more time but this time she stirs the mixture rapidly.
Answer:
It will go faster each time because she is stirring therefore the water can get to the salt faster than it just sitting at the top
Explanation:
0.41g of neon is held in a 200. mL container at 11 °C. Calculate the pressure in atm.
Answer:
2.39 atm
Explanation:
We'll begin by calculating the number of mole in 0.41 g of neon (Ne). This can be obtained as follow:
Mass of Ne = 0.41 g
Molar mass of Ne = 20 g/mol
Mole of Ne =.?
Mole = mass / molar mass
Mole of Ne = 0.41 / 20
Mole of Ne = 0.0205 mole
Next we shall convert 200 mL to L.
1000 mL = 1 L
Therefore,
200 mL = 200 mL × 1 L / 1000 mL
200 mL = 0.2 L
Next, we shall convert 11 °C to Kelvin temperature.
T(K) = T(°C) + 273
T(°C) = 11 °C
T(K) = 11 + 273
T (K) = 284 K
Finally, we shall determine the pressure. This can be obtained as follow:
Mole of Ne (n) = 0.0205 mole
Volume (V) = 0.2 L
Temperature (T) = 284 K
Gas constant (R) = 0.0821 atm.L/Kmol
Pressure (P) =?
PV = nRT
P × 0.2 = 0.0205 × 0.0821 × 284
P × 0.2 = 0.4779862
Divide both side by 0.2
P = 0.4779862 / 0.2
P = 2.49 atm
Therefore, the pressure of the gas is 2.39 atm
A common asteroid is in the first photograph. Haley's Comet is in the second photograph. What can be inferred about comets and asteroids? Answer A Both have orbits around the Earth that are ellipses B Both are miniature planets because they orbit the Sun C Both could be planetary fragments from the beginnings of solar system formation D Both are made of rock, ice, and solar dust from the beginning of the solar system
Answer:
D Both are made of rock ,ice and solar dust from the beginning of the solar system
Answer:
The answer is D
Explanation:
What does the cell theory state? Answer F All organisms are composed of a nucleus G All prokaryotes are composed of multiple cells H All prokaryotes are single celled organisms J All organisms are composed of cells
Answer:
(J) All organisms are composed of cells
Calculate the volume of solvent present in a 55.5%
by volume of 10.5 mL alcohol solution.
Answer:
I dont know
Explanation:
good luck
In calorimetry, energy is measured through heat transfer from one substance to
another. Which of the following is NOT a method of heat transfer?
Answer:
Refraction
Explanation:
Charge q is 1 unit of distance away from the source charge S. Charge p is two times further away. The force exerted
between S and q is the force exerted between S and p.
O 1/2
O 2 times
O 1/4
O 4 times
Answer:1/4
Explanation:
when rolling a number cube 500 times, how many times you expect to get a 3?
Answer:
[tex]\frac{250}{3}[/tex]
Explanation:
you can expect to get a 3 (theoretically) 1 time every 6 times you roll. A 1/6 chance.
Here's the equation:
[tex]\frac{1}{6} =\frac{x}{500}[/tex]
cross multiply (i think that's what it is called)
500=6x
divide by 6 on both sides:
x=[tex]\frac{250}{3}[/tex] or approx 83 times.
Hope this helps! Lmk if u have more questions <3
When 12.00 moles of potassium chlorate decomposes, how many dm3 of oxygen are produced at 325K and 188 kPa?
2KClO3 →2KCl + 3O2
show work pls
Answer:
258.71 dm³
Explanation:
We'll begin by calculating the number of mole of O₂ produced by the decomposition of 12 moles of KClO₃. This can be obtained as follow:
The balanced equation for the reaction is given below:
2KClO₃ —> 2KCl + 3O₂
From the balanced equation above,
2 moles of KClO₃ decomposed to produce 3 moles of O₂.
Therefore, 12 moles of KClO₃ will decompose to produce = (12 × 3)/2 = 18 moles of O₂.
Finally, we shall determine the volume of the O₂. This can be obtained as follow:
Temperature (T) = 325 K
Pressure (P) = 188 KPa
Number of mole (n) = 18 moles
Gas constant (R) = 8.314 KPa.dm³/Kmol
Volume (V) =?
PV = nRT
188 × V = 18 × 8.314 × 325
188 × V = 48636.9
Divide both side by 188
V = 48636.9 / 188
V = 258.71 dm³
Thus, 258.71 dm³ of oxygen were obtained from the reaction.
1. What are the five symbiotic relationships?
2. What is mutualism? Explain mutualism with an example and a picture.
3. What is commensalism? Explain with an example and a picture.
4. What is predation? Explain with an example and a picture.
5. What is parasitism? Explain with an example and a picture.
6. What is competition? Explain with an example and a picture.
Write a CER paragraph (5- 8 complete sentences) answering the following prompt:
Why are symbiotic relationships important in an ecosystem?
Answer:
1) There are five main symbiotic relationships: mutualism, commensalism, predation, parasitism, and competition.
2) The term mutualism can be simply defined as a relationship in which both species are mutually benefited. This relationship can either be within the species or between the two different species. ... Here ants are the mutualist and acacia trees is the host. The acacia tree provides home and food for the ants.
3) Commensalism is a type of symbiotic relationship in which one species benefits, while the other species is neither harmed nor helped. The species that gains the benefit is called the commensal. ... An example is a golden jackal (the commensal) following a tiger (the host) to feed on leftovers from its kills.
4) Predation is the interaction between organisms in which one organism known as the predator kills another organism which is known as prey. ... Examples of predation are a lion eating deer or a snake eating rats. This results in the transfer of energy from the prey to the predator.
5) Parasitism is generally defined as a relationship between the two living species in which one organism is benefitted at the expense of the other. The organism that is benefitted is called the parasite, while the one that is harmed is called the host. A few examples of parasites are tapeworms, fleas, and barnacles.
6) Competition is a negative interaction that occurs among organisms whenever two or more organisms require the same limited resource. ... For example, animals require food (such as other organisms) and water, whereas plants require soil nutrients (for example, nitrogen), light, and water.
Symbiotic relationships are important because they are a major driving force of evolution. This networking and cooperation among species allows them to survive better than they would as individuals.
How many grams of oxygen are required to burn 3.01 x 10^23 propane molecules?
A balloon is filled with 3.50 L of water at 24.0°C. What is the volume of the water at 307 K?
Answer:
what is the volume of the water at 307 k?
An experimental measurement was taken of 10.4mL and the actual measurement was 9.7mL. What is the percent error?
Answer:
13%
Explanation:
Give the ratio that balances out the following equation: ___Cr + ___Pb(NO3)4 ---> ___ Cr(NO3)3 + ____ Pb
the doge has the answer
Pb(NO3)4
What are the missing coefficients for C3H8 + o2 = Co2 +H2O
Answer: C3H8 + 5O2 = 3Co2 +4H2O
Explanation: Equations must be balanced
You must have the same amount of C
H and O on both sides of the equation