A gaseous mixture contains O₂ and another unknown gas in he molar
ratio of 4:1 effuses through a hole in 245 sec. Under similar conditions,
same volume of O, takes 220 sec to effuse. Find the molar mass of the
gas. (in g/mol)

Answers

Answer 1

The molar mass of the unknown gas is 28 g/mol.

What is Graham's law of effusion?

Graham's law of effusion states that the rate of effusion (the escape of gas molecules through a tiny hole) of a gas is inversely proportional to the square root of its molar mass, at constant temperature and pressure. This means that lighter gases effuse (escape through a hole) faster than heavier gases, all other factors being equal.

We can use Graham's law of effusion to solve this problem:

Rate of effusion is inversely proportional to the square root of molar mass.

Thus, we can write:

(rate of effusion of O₂) / (rate of effusion of the unknown gas) =

sqrt(molar mass of the unknown gas) / sqrt(molar mass of O₂)

Let's call the molar mass of the unknown gas "M". We can set up the following system of equations using the information given in the problem:

4/1 = (rate of effusion of O₂) / (rate of effusion of the unknown gas)

(rate of effusion of O₂) = 1/220

(rate of effusion of the unknown gas) = 1/245

Plugging in these values, we get:

4/1 = (1/220) / (1/245)

4/1 = 49/44

Solving for the rate of effusion of the unknown gas, we get:

(rate of effusion of the unknown gas) = (1/245) / (49/44) = 4/539

Now we can use Graham's law of effusion to find the molar mass of the unknown gas:

(rate of effusion of O₂) / (rate of effusion of the unknown gas) =

sqrt(molar mass of the unknown gas) / sqrt(molar mass of O₂)

(1/220) / (4/539) = sqrt(M) / sqrt(32)

Solving for M, we get:

M = 28 g/mol

Therefore, the molar mass of the unknown gas is 28 g/mol.

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Related Questions

the rate constant for a specific reaction has been determined at the following temps. 82 C, k= 3.97x10^-3 M^-1 x s^-1 , 125 C, k= 2.07x10^-2 ,M^-1 x s^-1. a) calculate the activation energy for the reaction

b) If data points were plotted in Arrhenius plot, what would the slope of the line be?

c) at what temp will the rate constant have k=1.00x10^-3 M^-1 x s^-1

Answers

The following formula can be used to calculate the activation energy: ln (k 1 /k 1) = É a /R x (1/S n 1 - 1/T 2). where. E an is the reaction's activation energy, expressed in J/mol.

What does a scientific reaction mean?

reaction definitions in science. reaction. one or more new compounds are formed as a result of the reorganization of the atoms and molecules of two substances when come into contact. Electrons of one material interact with all those of another to produce chemical reactions.

What chemical process changes one substance into another?

Chemical reaction is the process through which two or more compounds, known as reactants, change into one or more new ones, known as products. Chemical components or compounds make up substances. The atoms that make up the reactants are rearranged in a chemical reaction to produce various products.

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A student performed an experiment similar to that in Section B from the
"Use and Abuse of Aluminum and Its Compounds" lab. She started with a piece of aluminum foil with a mass of 0.0432 grams. She produced 0.5987 grams of alum crystals. What was her percent yield for the experiment?

Answers

Percent yield = 1566%, The percent yield is greater than 100%, which means that the student obtained more product than the theoretical yield.

What is the actual yield and the theoretical yield in an experiment?

The theoretical yield is the maximum amount of product that could be produced in a chemical reaction, based on stoichiometric calculations. The actual yield is the amount of product that is actually obtained from the reaction in a laboratory experiment.

To calculate the percent yield of the experiment, we need to compare the actual yield to the theoretical yield.

The balanced chemical equation for the formation of alum from aluminum and potassium hydroxide is:

2 Al + 2 KOH + 4 H₂O + 1/2 O₂ → KAl(SO₄)₂·12H₂O

From this equation, we can see that the mole ratio of aluminum to alum is 2:1. This means that for every 2 moles of aluminum used, we should theoretically obtain 1 mole of alum.

First, we need to convert the mass of aluminum foil used to moles of aluminum:

0.0432 g Al × 1 mol Al/26.98 g Al = 0.001600 mol Al

Next, we can use the mole ratio to calculate the theoretical yield of alum:

Theoretical yield = 0.001600 mol Al × 1 mol KAl(SO₄)₂·12H₂O/2 mol Al × 474.39 g KAl(SO₄)₂·12H₂O/1 mol KAl(SO₄)₂·12H₂O

= 0.0382 g KAl(SO₄)₂·12H₂O

Now we can calculate the percent yield:

Percent yield = actual yield/theoretical yield × 100%

Actual yield = 0.5987 g

Percent yield = 0.5987 g/0.0382 g × 100% = 1566%

The percent yield is greater than 100%, which means that the student obtained more product than the theoretical yield. This could be due to experimental error, such as incomplete drying of the crystals or loss of product during the experiment. It's also possible that the student accidentally used more aluminum foil than intended.

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4- Calculate the pH of 0.3 M NH, where is K = 1.7 x 10

Answers

The pH of .3 M NH, where is K = 1.7 x 10^-5 is 11.87 calculated from the equation of dissociation constant.

How can pH be determined?

Kb= [A] /[A + ][X− ]

​1.7×10 −5 = x ^2 /0.3

⇒x= 7.5 ×10 −3

∴[OH − ][H + ]=7.5 ×10 −3

[H + ] =10 ^−14 ⇒pH=11.87

When describing the acidity or basicity of an aqueous solution, chemists use the pH scale, which is also known as acidity and previously stood for "potential of hydrogen". Greater pH values are seen in basic or alkaline solutions than acidic solutions.

Potential hydrogen is the meaning of the acronym pH, which indicates how much hydrogen is present in liquids and how active the hydrogen ion is.

As a first step, we shall ascertain the pKa of the solution before calculating its Ka. When a solution reaches the equivalence point, its pH and pKa are equal. So, by using a titration curve and the Ka = - log pKa equation, we may rapidly ascertain the value of Ka.

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How does a Sulfur 2 ion differ from a neutral Sulfur atom?
O
Mass number
Atomic number
Number of electrons
Proton number

Answers

Answer:

o

Mass number

Atomic number

Number of electrons

Proton number

Explanation:

Liquid octane CH3CH26CH3 will react with gaseous oxygen O2 to produce gaseous carbon dioxide CO2 and gaseous water H2O. Suppose 6.9 g of octane is mixed with 42.2 g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Round your answer to 2 significant digits.

Answers

The maximum mass of carbon dioxide that could be produced from 6.9 g of octane and 42.2 g of oxygen is 21.3 g, rounded to 2 significant digits.

What is Octane?

Octane is a hydrocarbon with the chemical formula [tex]C_{8} H_{18}[/tex] It is an organic compound belonging to the alkane group, which means it consists of only carbon (C) and hydrogen (H) atoms bonded together by single covalent bonds. Octane is a colorless liquid with a molecular weight of approximately 114 g/mol and is commonly used as a component in gasoline or fuel for internal combustion engines.

From the balanced equation, we know that 1 mole of octane reacts with 12.5 moles of oxygen to produce 8 moles of carbon dioxide. Therefore, 0.0605 mol of octane would require 0.0605 mol x 12.5 = 0.75625 mol of oxygen to fully react.

Since we have only 1.32 mol of oxygen, which is in excess compared to the 0.75625 mol required by octane, oxygen is the excess reactant, and octane is the limiting reactant.

Now, we can use the stoichiometry of octane to carbon dioxide to calculate the maximum mass of carbon dioxide produced:

From the balanced equation, we know that 1 mole of octane produces 8 moles of carbon dioxide.

Molar mass of carbon dioxide (CO2) = 44.01 g/mol

Maximum moles of carbon dioxide produced from octane = 0.0605 mol x 8 = 0.484 mol

Maximum mass of carbon dioxide produced from octane = 0.484 mol x 44.01 g/mol = 21.3 g

Remember to round the final answer to 2 significant digits as requested.

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In the reaction below, which species is reduced?
3Ag2S(s) + 8W(aq) + 2N03-(aq) - 6Ag+(aq) + 3S(s) + 2NO(g) + 4H20
A. Ag2S
B. H+
C. N03-
D. NO
E. S The sum of the oxidation numbers of all the atoms in the peroxydisu1fate ion, S20g2-, is
A. -2
B. +2
C. +4
D. +5
E. +6

Answers

In the peroxodisulfate ion, Peroxydisulfate-, all the atoms have oxidation values that add up to +6.

Peroxydisulfate has what purpose?

Most often, the polymerization of different alkenes, such as styrene, acrylonitrile, and fluoroalkenes, is started using salts of peroxydisulfate. The homolysis of peroxydisulfate causes polymerization to begin. 2 [Peroxydisulfate] [Sulfate]

Ag: +1

Sulfur: 0

Nitrogen: +2 (in Nitric oxide)

Oxygen: -2 (in Water)

Hydrogen: +1 (in Water)

The peroxodisulfate ion, Peroxydisulfate-, consists of one disulfate (Peroxydisulfate-) group and two peroxy (Oxygen2-) groups. Normal oxygen oxidation number is 2, however in a peroxy group it is -1. The charge of the ion, which is -2, is equal to the total sum of the oxidation numbers of all the atoms in the ion. As a result, we may write:

2(-1) + 2x + 8(-2) = -2

-2 + 2x - 16 = -2

2x = 12

x = +6

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A sample of an ideal gas at 473K, 2.01bar pressure has a volume of 78.3L. The gas is allowed to expand until the pressure reaches 1.00bar. What is the final volume of gas in L?

Answers

The final volume of the ideal gas is 156.6 L.

When an ideal gas sample is let to expand?

A sample of an ideal gas is allowed to expand adiabatically while producing external work (W) at first. The volume is then maintained at its new value with the help of heat Q until the pressure returns to its initial level.

We can use the combined gas law to solve this problem:

(P1 × V1) / T1 = (P2 × V2) / T2

where P1, V1, and T1 are the initial pressure, volume, and temperature, respectively, and P2 and V2 are the final pressure and volume, respectively. Since the gas is kept at a constant temperature, we can simplify this to:

P1 × V1 = P2 × V2

Plugging in the given values, we get:

2.01 bar × 78.3 L = 1.00 bar × V2

Solving for V2, we get:

V2 = (2.01 bar × 78.3 L) / 1.00 bar = 157 L

Therefore, the final volume of gas is 157 L.

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A student mixes 100. mL of 0.25 M HCl(aq) with 200. mL of 0.50 M HClO4(aq) and then dilutes the mixture with distilled water to a total volume of 500. mL. The [H3O+] in the final solution is closest to
(A) 0.0025 M
(B) 0.12 M
(C) 0.25 M
(D) 0.75 M

Answers

Answer:

The answer is B: 0.0025 M

According to molar concentration and dilution concept, the  [H₃O+] in the final solution is closest to 0.05 M.

What is molar concentration?

Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.

The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.

In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of 2 solutions concentrated and diluted it is calculated as, M₁V₁=M₂V₂ substitution gives M₂=0.25×100/500=0.05

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Does anyone know how to solve this? (Picture Provided)

Answers

For chemical reaction (3), the standard enthalpy change is 279.0 kJ.

How to calculate enthalpy change?

To find the standard enthalpy change for reaction (3), use Hess's Law which states that the overall enthalpy change of a reaction is independent of the pathway between the initial and final states.

Obtain the required reaction by subtracting the enthalpy change of reaction (2) from that of reaction (1) as follows:

(1) 2C(s) + H₂(g) → C₂H₂(g) ΔH° = 226.7 kJ

(2) 2C(s) + 2H₂(g) → C₂H₄(g) ΔH° = 52.3 kJ

(3) C₂H₂(g) + H₂(g) → C₂H₄(g) ΔH° = ?

To get the enthalpy change for reaction (3), flip the reaction (2) and multiply by 1/2 so that the reactants match those in reaction (1):

(2) C₂H₄(g) → 2C(s) + 2H₂(g) ΔH° = -52.3 kJ

Now write the reaction (3) as the difference between (1) and (2):

(1) 2C(s) + H₂(g) → C₂H₂(g) ΔH° = 226.7 kJ

(2) C₂H₄(g) → 2C(s) + 2H₂(g) ΔH° = -52.3 kJ

(3) C₂H₂(g) + H₂(g) → C₂H₄(g) ΔH° = 279.0 kJ

Therefore, the standard enthalpy change for reaction (3) is 279.0 kJ.

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why does glass containing an iced beverage feel cold

Answers

Answer:

Molecules in the skin are moving faster than molecules in the glass.

Explanation:

Put it in your own words.

Answer:

The energy from the ice transferred to the glass.

Very quick can someone like help me

Answers

Answer:

Explanation:

dilute solutions of hydrochloric acid (HCl), sulphuric acid (H₂SO₄), and nitric acid (HNO₃) react with active metals to produce a salt and hydrogen gas.

Active metals react strongly and quickly with other elements and compounds due to the electrons in its structure and its ease of sharing the electrons with other elements.

The most active metals are found in Groups 1  and 2 of the Periodic Table (i.e. the left side), and include lithium, potassium, magnesium, and calcium. Metals such as aluminium, lead, and zinc, are less active than magnesium or calcium, but are generally still labelled as 'active'. Metals such as copper, gold, or silver are inactive and will not react.

Therefore, in the provided question, all the metals listed, except for copper, will produce a metal salt + hydrochloric acid. Copper will not react.

In general:

metal + HCl = metal chloride + H₂ metal + H₂SO₄ = metal sulphate + H₂metal + HNO₃ = metal nitrate + H₂

A precipitation reaction involves the formation of a precipitate when aqueous solutions are mixed. Not all combinations of aqueous solutions produce precipitates, and it is important to be able to predict the ones that do.
Complete and balance the molecular equation for the reaction between aqueous solutions of lithium fluoride and potassium chloride, and use the states of matter to show if a precipitate forms.
Part 2 : Write the complete ionic equation for the reaction that takes place when aqueous solutions of lithium fluoride and potassium chloride are mixed.

Answers

In this reaction, aqueous solutions of lithium fluoride and potassium chloride are mixed, but no precipitate forms. This is because the products of the reaction (LiCl and KF) are both soluble in water, and therefore remain in the aqueous state.

What is reaction?

Reaction is a process in which a system changes in response to an external stimulus. It is a response to an action, event, or phenomenon, and it is typically expressed in the form of an observable physical or mental change. Reactions can take place in a variety of forms, including chemical reactions, physical reactions, and psychological reactions. Chemical reactions are the most common type of reaction and involve the rearrangement of atoms and molecules in order to form new substances. Physical reactions involve changes in the physical properties of a system, such as changes in temperature, pressure, or volume. Psychological reactions include changes in behavior and emotion.

The complete and balanced molecular equation for the reaction between aqueous solutions of lithium fluoride and potassium chloride is:
LiF (aq) + KCl (aq) → LiCl (aq) + KF (aq)
The complete ionic equation for this reaction is:
Li+ (aq) + F- (aq) + K+ (aq) + Cl- (aq) → Li+ (aq) + Cl- (aq) + K+ (aq) + F- (aq)

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Carbon dioxide is produced by the burning of fossil fuels which then leads to higher levels of carbon dioxide in the atmosphere. This gas captures heat (greenhouse gas), so the temperature rises on earth (global warming). If there are 3.2 kg of fuel in a gallon of octane (C8H18) and idling for 15 minutes twice a day Monday- Friday burns half a gallon of gas a day, how many grams of fuel do you use in a week. Then convert the grams to carbon dioxide to determine the amount of carbon dioxide produced by all this idling.

Answers

The amount of carbon dioxide produced by all the idling described in the problem would be 89.6 kg per week.

What is Global Warming?

Global warming refers to the long-term increase in Earth's average surface temperature, primarily caused by human activities such as burning fossil fuels (coal, oil, and natural gas), deforestation, and industrial processes that release large amounts of greenhouse gases into the atmosphere.

Using the atomic masses from the periodic table, we get:

Molar mass of octane = (8 x 12.01 g/mol) + (18 x 1.01 g/mol) = 114.22 g/mol

Since the molecular formula of octane (C8H18) contains 8 carbon atoms, it produces 8 molecules of carbon dioxide (CO2) per molecule of octane during combustion.

So, the amount of carbon dioxide produced by burning 11,200 grams of octane would be:

11,200 g * (8 x 1 mol CO2 / 1 mol octane) = 89,600 g or 89.6 kg of carbon dioxide produced in a week.

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KI Which type of reaction is this equation an example of? CH3OH + O2 CO₂ + 2H₂O heat​

Answers

this is a combustion reaction, when a compound or substance reacts in the presence of oxygen and results in the formation of carbon dioxide and water along with the release of heat are known as combustion reaction

URGENT!! WILL MARK ANYONE WITH ALL ANSWERS AS BRAINLIEST!!!

Answers

Answer:

1) 9 moles

2) 8.75 moles

3) 1.76 moles

4) 10.2 moles

Explanation:

Okay so mole ratio is 2:1

So, 9 moles of HI is required for 4.5 moles of Iodine gas

Mol ratio of water to CaCl2 is 2:1

So, 17.5 moles of water produced is (17.5/2) moles of CaCl2 i.e. 8.75 moles

Okay so mol ratio of Hydrogen to NH3 is 3:2

So, 2.64 moles of hydrogen is (2.64 * 2)/3 moles of NH3 i.e. 1.76 moles

Once again, mol ratio of Hydrogen to NH3 is 3:2

When 15.3 moles of hydrogen is used, (15.3 * 2)/3 moles of NH3 i.e. 10.2 moles

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A 2.6 mol sample of N2 is held in a 4191 mL balloon at 89.9 atm. What temperature (in Celcius) is the gas at? Answer to one decimal place.

Answers

To convert to Celsius, we subtract 273.15 from the Kelvin temperature, giving us a final answer of 42.1°C.

What is temperature?

Temperature is a physical quantity that measures the average kinetic energy of the particles in a system. It is an important parameter for understanding the behavior of matter and the underlying physical processes at work. Temperature is measured in units such as degrees Celsius (°C), Fahrenheit (°F), Kelvin (K), or Rankine (°R). Temperature affects the rate at which chemical reactions occur and the movement of particles in solids, liquids, and gases.

The ideal gas law states that PV = nRT,
where n is the number of moles,
P is the pressure,
V is the volume, R is the ideal gas constant (8.314 J/molK), and
T is the temperature in Kelvin.
Rearranging the equation, we get T = (PV)/(nR).
Plugging in our values, we get T = (89.9 atm * 4191 mL)/(2.6 mol * 8.314 J/molK) = 115.2 K.
To convert to Celsius, we subtract 273.15 from the Kelvin temperature, giving us a final answer of 42.1°C.

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The diagram below illustrates that the mass of an atom of element X is equivalent to the total mass of 7 hydrogen atoms. X H H H H H H X H 14​

Answers

The total mass of protons and neutrons makes up an element's atomic mass. Lithium is the element X; it has a mass of 6.941 u.

What is element?

When an atom has the same number of protons in its atomic nucleus, it is said to be an element. The number of protons in the nucleus of each element's atoms, or atomic number, serves as the element's sole means of identification.

Seven hydrogen atoms will weigh 7.056 g as each hydrogen atom has an atomic mass of 1.008. The periodic chart shows that an atomic mass of 7.056 g is the one that is closest to that of a lithium atom (6.941 u).

Seven hydrogen atoms have a mass comparable to one lithium atom in the periodic table, based on their mass. With an atomic mass of 6.941 g/mol, the lithium atom bears the atomic number 3.

Lithium is  the name of element X.

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pls help!!!
a compound is found to be 51.39% carbon, 8.64% hydrogen, and 39.97% nitrogen. it has a molecular molar mass of 140.22 g/mol. what is the molecular formula.
show work pls!!

Answers

The molecular formula of the compound, given that it contains 51.39% carbon, 8.64% hydrogen, and 39.97% nitrogen is C₆H₁₂N₄

How do i determine the molecular formula?

To obtain the molecular formula, we must first determine the empirical formula. Details on how to obtain the empirical formula is given beloww:

Carbon (C) = 51.39%Hydrogen (H) = 8.64%Nitrogen (N) = 39.97%Empirical formula =?

Divide by their molar mass

C = 51.39 / 12 = 4.283

H = 8.64 / 1 = 8.64

N = 39.97 / 14 = 2.855

Divide by the smallest

C = 4.283 / 2.855 = 1.5

H = 8.64 / 2.855 = 3

N = 2.855 / 2.855 = 1

Multiply through by 2 to express in whole number

C = 1.5 × 2 = 3

H = 3 × 2 = 6

N = 1 × 2 = 2

Thus, we can conclude that the empirical formula is C₃H₆N₂

Finally, we shall determine the molecular formula. Details below

Empirical formula = C₃H₆N₂Molar mass of compound = 140.22 g/molMolecular formula =?

Molecular formula = empirical × n = mass number

[C₃H₆N₂]n = 140.22

[(12×3) + (1×6) + (14×2)]n = 140.22

70n = 140.22

Divide both sides by 70

n = 140.22 / 70

n = 2

Molecular formula = [C₃H₆N₂]n

Molecular formula = [C₃H₆N₂]₂

Molecular formula = C₆H₁₂N₄

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The oxides SO2 and N2O5 will form what acids?

Answers

When SO2 dissolves in water, it forms sulfurous acid (H2SO3), which can be further ionized to form bisulfite ions (HSO3-) and sulfite ions (SO32-). The reaction can be represented as follows:

SO2 + H2O → H2SO3

N2O5, on the other hand, reacts with water to form nitric acid (HNO3), which is a strong acid. The reaction can be represented as follows:

N2O5 + H2O → 2HNO3

Therefore, SO2 forms sulfurous acid (H2SO3) and N2O5 forms nitric acid (HNO3) when they react with water.

I need to find the average percent recovery

Answers

Consider that after recrystallization, you obtained 7.0 g of dry pure substance from 10.0 g of impure material. Your recovery rate is then 70% (7/10 × 100).

What is the typical recrystallization percentage?

Recrystallization recovery percentages are often lower than 100%, though occasionally they might be higher (see the following issue). This is brought on by impurity loss, material that was left in the liquid solution after dissolving, and "mechanical losses."

What drives our % recovery calculations?

The amount if pure compound that is present in the finished chemical synthesis product is calculated using the percent recovery. The ratio of actual yield to theoretical yield is used to compute percent yield. The ratio of the pure compound to the starting compound is used to calculate percent recovery.

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What is the molarity of a solution containing 5.035 grams of FeCIe in enough water to make 500 mL of solution?

Answers

To calculate the molarity of the solution, we first need to determine the number of moles of FeCl2 present in the solution.

The molar mass of FeCl2 is 126.75 g/mol (55.85 g/mol for Fe and 35.45 g/mol for Cl).

Number of moles of FeCl2 = mass of FeCl2 / molar mass of FeCl2
= 5.035 g / 126.75 g/mol
= 0.0397 mol

Now we can calculate the molarity of the solution:

Molarity = moles of solute / liters of solution

Since we have 500 mL of solution, we need to convert it to liters by dividing by 1000:

Liters of solution = 500 mL / 1000 mL/L
= 0.5 L

Now we can calculate the molarity:

Molarity = moles of solute / liters of solution
= 0.0397 mol / 0.5 L
= 0.0794 M

Therefore, the molarity of the solution containing 5.035 grams of FeCl2 in enough water to make 500 mL of solution is 0.0794 M.

What is true of spontaneous reactions?
O They are indicated by a negative change in Gibbs free energy.
O They have a positive value of AS.
O They are instantaneous.
O They always release heat.

Help 20pts

Answers

1. They are indicated by a negative change in Gibbs free energy.

Explanation: Spontaneous reactions are those that occur without any external input of energy. A negative change in Gibbs free energy (ΔG) indicates that a reaction is spontaneous. The other options do not always hold true for spontaneous reactions. The value of entropy change (ΔS) can be positive or negative, spontaneous reactions are not necessarily instantaneous, and they do not always release heat.

The calcium and magnesium in a urine sample were precipitated as oxalates. A mixed precipitate of calcium oxalate (CaC2O4) and magnesium oxalate (MgC2O4) resulted and was analysed by gravimetry. The formed precipitate mixture was heated to form calcium carbonate (CaCO3) and magnesium oxide (MgO) with a total mass of 0.0433 g. The solid precipitate mixture was ignited to form CaO and MgO, the resulting solid after ignition weighed 0.0285 g. What was the mass of calcium in the original sample? All answers should be reported with the correct significant figures

Answers

The mass of calcium in the original urine sample would be 0.0140 g.

Stoichiometric problem

First, we need to find the masses of calcium and magnesium oxalates in the original sample. Let x be the mass of calcium oxalate and y be the mass of magnesium oxalate. Then we have:

x + y = mass of the mixed oxalate precipitate

Next, we need to use the information given to find the mass of calcium in the original sample. The mass of calcium oxide formed after ignition is equal to the mass of calcium oxalate in the original sample. We can calculate the mass of calcium oxide using the mass of calcium carbonate formed and the molar mass ratio of calcium carbonate to calcium oxide.

The balanced chemical equations for the reactions are:

CaC2O4 -> CaCO3 + CO2

CaCO3 -> CaO + CO2

The molar mass of CaCO3 is 100.09 g/mol, and the molar mass of CaO is 56.08 g/mol.

From the given information, we have:

0.0433 g = (x + y)(100.09 g/mol + 80.15 g/mol) / (128.10 g/mol + 80.15 g/mol)

0.0285 g = x(56.08 g/mol) + y(40.31 g/mol)

Solving these equations simultaneously, we get:

x = 0.0140 g

y = 0.0053 g

Therefore, the mass of calcium in the original sample (which is equal to the mass of calcium oxide formed after ignition) is:

0.0140 g

So the mass of calcium in the original sample is 0.0140 g.

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Determine how many grams (g) of carbohydrate are in a sandwich that
contains 475 total Calories, 10 g of fat, and 25 g of protein.

Answers

The sandwich contains approximately 71.25 grams of carbohydrates.

What do you understand by the term calories?

Calories are a unit of measurement used to quantify the amount of energy contained in food and beverages. The number of calories in a particular food is determined by the amounts of carbohydrates, fats, proteins, and other nutrients it contains.

To determine the number of grams of carbohydrates in the sandwich, we need to use the fact that carbohydrates, fats, and proteins have different calorie densities. Specifically, carbohydrates and proteins each contain about 4 calories per gram, while fats contain about 9 calories per gram.

First, let's calculate the total number of calories coming from the fat and protein in the sandwich:

Total calories = calories from carbohydrates + calories from fat + calories from protein

475 Calories = calories from carbohydrates + 10g x 9 Calories/g + 25g x 4 Calories/g

475 Calories = calories from carbohydrates + 90 Calories + 100 Calories

475 Calories - 190 Calories = calories from carbohydrates

285 Calories = calories from carbohydrates

Now that we know the number of calories from carbohydrates, we can use the calorie density of carbohydrates to determine the number of grams of carbohydrates:

285 Calories = carbohydrates in grams x 4 Calories/g

71.25 g = carbohydrates in grams

Therefore, the sandwich contains approximately 71.25 grams of carbohydrates.

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Does anyone know how to solve this? (Picture Provided)

Answers

Therefore, the standard enthalpy change for reaction (3) is -152.6 kJ.

What is the standard enthalpy change of the reaction?

To determine the standard enthalpy change for reaction (3), we can use Hess's law, which states that the overall enthalpy change for a reaction is the sum of the enthalpy changes for each step of the reaction.

We can see that reaction (1) has the same products as reaction (3) but in reverse order. We can use reaction (1) to reverse the formation of FeO:

2Fe(s) + O2(g) → 2FeO(s) ΔH° = -544.0 kJ

2FeO(s) → 2Fe(s) + O2(g) ΔH° = +544.0 kJ (reversed)

We can also use reaction (2) to form ZnO, which is a product in reaction (3):

2Zn(s) + O2(g) → 2ZnO(s) ΔH° = -696.6 kJ

Now, we can add the two reactions to get the overall reaction (3):

2FeO(s) + 2Zn(s) → 2Fe(s) + 2ZnO(s)

We add the enthalpies of the two reactions to get the enthalpy change for reaction (3):

ΔH° = (+544.0 kJ) + (-696.6 kJ)

ΔH° = -152.6 kJ

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NEED HELP ON THIS QUESTION

Answers

54.2 g of CaCl2 must be dissolved in 1000 g of water to raise the boiling point to 100.75°C.

The mass of CaCl2

To solve this problem, we can use the formula:

ΔTb = Kb × m × i

where ΔTb is the boiling point elevation, Kb is the molal boiling point elevation constant for water, m is the molality of the solution, and i is the van't Hoff factor, which represents the number of particles into which the solute dissociates.

We can rearrange this formula to solve for the molality of the solution:

m = ΔTb / (Kb × i)

We know that ΔTb is 0.75°C (100.75°C - 100°C), Kb is 0.51°C/m, and i for CaCl2 is 3 (since it dissociates into 3 ions in water). Substituting these values, we get:

m = 0.75°C / (0.51°C/m × 3) = 0.490 m

To find the mass of CaCl2 needed to make a 0.490 m solution in 1000 g of water, we can use the formula:

moles of solute = molality × mass of solvent (in kg)

We convert 1000 g of water to 1 kg, and then use the molecular weight of CaCl2 to convert from moles to grams:

moles of CaCl2 = 0.490 m × 1 kg = 0.490 mol

mass of CaCl2 = 0.490 mol × 110.98 g/mol = 54.2 g

Therefore, 54.2 g of CaCl2 must be dissolved in 1000 g of water to raise the boiling point to 100.75°C.

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What is the sign of the entropy change of the universe at room temperature (298.15 K), and is this process spontaneous at room temperature?

a.)
negative, not spontaneous
b.)
positive, spontaneous
c.)
positive, not spontaneous

Answers

The sign of entropy change of the universe at room temperature is b.) positive, spontaneous

What is entropy ?

The concept of entropy is a measure of the degree of disorder or randomness in a system. In thermodynamics, it is a measure of the number of ways in which the energy of a system can be distributed among its constituent particles.

The second law of thermodynamics states that the entropy of the universe always increases for spontaneous processes. This means that, in any spontaneous process, the total entropy change of the system and its surroundings must be positive.

At room temperature (298.15 K), a process that is spontaneous will always result in an increase in the entropy of the universe, and the sign of the entropy change will be positive.

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[1 mole = 22.4 Liters; 1 mole = 6.02 x 10 23 atoms/molecules]
1. Determine the number of grams in 0.89 moles of carbon dioxide, CO2. Show all work.

Answers

Answer: 40. g

Explanation:

To find the grams in 0.89 moles of CO2, we just need to use the molar mass of CO2. The molar mass which tells us how many grams are in a mole for an element or compound.

The molar mass of CO2 is equal to the molar mass of carbon, 12.0107, and 2 oxygens, 2*15.9994 (you can find the molar mass of an element on any periodic table). Add these, and you get the molar mass of CO2 to be 44.01 g/mol, a helpful value to remember.

Now, just multiply the molar mass by the amount of moles to find grams.

[tex]\frac{44.01g}{mole} * 0.89mole[/tex], moles cancel out, [tex]\frac{44.01g}{mole} * 0.89mole=40.48g[/tex]

There are 2 significant figures in the question, so I will round this answer to 2 significant figures, 40. g

How many moles is 3.4 g of HCI?

Answers

3.4 g of HCl is therefore equivalent to roughly 0.0932 moles of HCl.

What is the HCI's mole count?

Since each molecule of HCl contains one mole of hydrogen and one mole of chlorine, the mole quantity of HCl equals the mole quantity of hydrogen and chlorine in the sample.

Approximately 36.46 g/mol is the molar mass of hydrochloric acid (HCl). We must divide the mass by the molar mass to determine the number of moles of HCl in 3.4 g of HCl:

Mass of HCl / molar mass of HCl equals moles of HCl.

3.4 grams per 36.46 grams per mole of HCl

A mole of HCl is equal to 0.0932 mol.

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4. If 7.37 liters of HCI reacts with Al, how many moles of hydrogen, H₂,can be produced?

Answers

As a result, aluminium (Al) and 7.37 litres of hydrochloric acid (HCl) can react to produce 225.46 moles of hydrogen gas (H2).

8.0 moles of Al interacting with HCl can produce how many moles of H2?

As a result, when 8 moles of aluminium are entirely consumed during the process of dissolving it in HCl solution, 12 moles of hydrogen gas are created.

The chemical reaction between aluminium (Al) and hydrochloric acid (HCl) has the following balanced chemical equation:

[tex]3 H2 + 2 AlCl3 = 2 HCl + 2 Al[/tex]

According to the equation, 2 moles of HCl result in 3 moles of H2. In order to determine the amount of H2 generated, we must first determine how many moles of HCl are contained in 7.37 litres of acid.

The following formula can be used to determine the quantity of HCl:

Volume in litres times concentration in moles per litre equals moles.

Since the HCl concentration is not specified in the inquiry, we are unable to immediately calculate the moles. However, we may convert the volume in litres to the mass in grams using the density of HCl, and then use the molar mass of HCl to calculate the number of moles.

At standard circumstances (0 °C and 1 abm), HCl has a density of roughly 1.49 g/mL. As a result, 7.37 litres of HCl have the following mass:

Density equals mass, therefore 7.37 L times 1.49 g/mL equals 10.9763 kg.

Since HCl has a molar mass of about 36.46 g/mol, there are the following moles of HCl:

[tex]10.9763 kg / 36.46 g/mol = 300.61 mol is the formula for moles of HCl.[/tex]

Now, we can determine the number of moles of H2 created using the mole ratio from the balanced equation: moles of[tex]H2 = (moles of HCl / 2) x (3/2) = (300.61 mol / 2) x (3/2) = 225.46 mol[/tex]

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