Question 1

Aspirin is the common name for acetyl salicylic acid, C₉H₈O₄.One tablet contains 0.325 g of aspirin.How many moles of aspirin is this?

Accepted Answer

The molar mass of aspirin (C9H8O4) can be calculated as:

9(12.01 g/mol) + 8(1.01 g/mol) + 4(16.00 g/mol) = 180.16 g/mol

To find the number of moles in 0.325 g of aspirin, we use the formula:

moles = mass/molar mass

moles = 0.325 g / 180.16 g/mol

moles = 1.80 × 10^-3 mol

Therefore, the correct answer is B, 1.80 × 10^-3 mol.

Question 2

Classify the following reaction: Ce⁴⁺(aq) + Fe²⁺(aq) → Ce³⁺(aq) + Fe³⁺(aq)

Accepted Answer

This reaction involves the transfer of electrons, where Ce^4+ is reduced to Ce^3+ and Fe^2+ is oxidized to Fe^3+, indicating an oxidation-reduction (redox) reaction.

Question 3

Methanol (CH₃OH) is the fuel used by racecars in the Indianapolis 500.It burns in the engine according to the equation below.How many moles of oxygen gas are necessary to react completely with 425 moles of methanol? 2CH₃OH(l) + 3O₂(g) → 2CO₂(g) + 4H₂O(g)

Accepted Answer

The answer of Methanol (CH₃OH) is the fuel used by...

Question 4

The chemical equation below is not balanced.What is the coefficient of iron when the equation is balanced with smallest whole number coefficients? Fe(s) + O₂(g) → Fe₂O₃(s)

Accepted Answer

The answer of The chemical equation below is not balanced.What...

Question 5

How many moles of hydrogen gas are needed to react with oxygen to form one mole of water? 2H₂(g) + O₂(g) → 2H₂O(l)

Accepted Answer

According to the balanced chemical equation, 2 moles of hydrogen gas are required to react with 1 mole of oxygen gas to form 2 moles of water. Therefore, to form one mole of water, 1 mole of hydrogen gas is required.

Question 6

Choose the best classification of the reaction represented by the following equation: C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H₂O(l)

Accepted Answer

The reaction involves a substance reacting with oxygen to produce carbon dioxide and water, which is characteristic of a combustion reaction.

Question 7

Which of the choices is the correctly balanced form of the following equation? C₆H₁₄(l) + O₂(g) → CO₂(g) + H₂O(l)

Accepted Answer

The correct answer involves doubling the initial compound to balance the equation with the products, requiring 19 oxygen molecules to balance the equation, resulting in 12 CO and 14 H2O molecules.

Question 8

Methanol (CH₃OH) is the fuel used by racecars in the Indianapolis 500.It burns in the engine according to the equation below.How many moles of oxygen gas are necessary to react completely with 12.5 L of methanol? [Density: CH₃OH, 0.7910g/mL; Molar mass: CH₃OH, 32.05 g/mol] 2CH₃OH(l) + 3O₂(g) → 2CO₂(g) + 4H₂O(g)

Accepted Answer

The answer of Methanol (CH₃OH) is the fuel used by...

Question 9

Prozac, a drug prescribed to treat depression, has the formula C₁₇H₁₈F₃NO.If a patient was administered 15.0 mg of Prozac, how many moles of Prozac did he receive? [Molar mass: Prozac, 309.36 g/mol]

Accepted Answer

1. First, calculate the mass of 1 mole of Prozac: 
Molar mass of Prozac = 309.36 g/mol 
1 mole of Prozac = 309.36 g

2. Then, calculate the number of moles in 15.0 mg of Prozac: 
15.0 mg = 0.015 g 
Number of moles = (0.015 g) / (309.36 g/mol) = 4.85 × 10^-5 mol

Therefore, the answer is A) 4.85 × 10^-5 mol.

Question 10

Consider the hypothetical reaction: 3A₂ + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B, what is the maximum amount of C that can be formed?

Accepted Answer

The limiting reactant is B since it has a lower mole ratio compared to A (2.0 moles of B to 6.0 moles of A, with the reaction requiring 2 moles of B for every 3 moles of A). Therefore, 2.0 moles of B can produce 1.0 mole of C according to the stoichiometry of the reaction.

Question 11

Consider the following precipitation reaction.Which of the following correctly identifies the spectator ions in this reaction? Na₂S(aq) + CuSO₄(aq) → Na₂SO₄(aq) + CuS(s)

Accepted Answer

The spectator ions are the ions that do not participate in the chemical reaction and remain in their original form. In this case, the Na+ and S2- ions are present on both sides of the reaction, meaning they do not participate in the reaction and are the spectator ions. The Cu2+ and SO42- ions, on the other hand, do participate in the reaction and are not spectator ions. Therefore, the correct answer is C since it identifies only the spectator ions as Na+ and S2-.

Question 12

What is the formula mass of carbon dioxide? [Atomic masses: C, 12.01 amu; O, 16.00 amu]

Accepted Answer

The formula mass (or molar mass) of a compound is calculated by adding up the atomic masses of all the atoms in the formula. The formula for carbon dioxide is CO2, which contains one carbon atom (12.01 amu) and two oxygen atoms (16.00 amu each). Therefore, the formula mass of carbon dioxide is:

1(12.01 amu) + 2(16.00 amu) = 44.01 amu

Question 13

Choose the best classification of the reaction represented by the following equation: Na₂SO₄(aq) + Ba(OH)₂(aq) → BaSO₄(s) + 2NaOH(aq)

Accepted Answer

This is a double-replacement reaction because the positive ions of the two reactants (Na+ and Ba2+) switch places to form the products (BaS and NaOH).

Question 14

Choose the best classification of the reaction represented by the following equation: 2KClO₃(s) → 2KCl(s) + 3O₂(g)

Accepted Answer

The reaction is a decomposition reaction because one reactant (KClO3) breaks down into two or more products (KCl and O2).

Question 15

Classify the following reaction: H₂SO₄(aq) + 2KOH(aq) → K₂SO₄(aq) + 2H₂O(aq)

Accepted Answer

The reaction involves an acid-base reaction between H₂SO₄(aq) and KOH(aq), resulting in the formation of K₂SO₄(aq) and H2₂O(aq).

Question 16

Incomplete combustion occurs when there is insufficient oxygen to react with a compound.The suffocating gas carbon monoxide is a product of incomplete combustion.How many moles of oxygen gas are required for the complete combustion of 11.0 moles of C₆H₁₄, a component of gasoline? C₆H₁₄(l) + 19O₂(g) → 12CO₂(g) + 14H₂O(l)

Accepted Answer

The answer of Incomplete combustion occurs when there is insufficient...

Question 17

When solutions of sodium sulfide and copper(II) sulfate are mixed, a precipitate of copper(II) sulfide is formed.What is the net ionic equation for this reaction?

Accepted Answer

The net ionic equation shows only the species that actually participate in the reaction. In this case, sodium and sulfate ions do not participate in the formation of the precipitate. Therefore, the net ionic equation is:

Cu2+ (aq) + S2- (aq) → CuS (s)

Question 18

How many molecules are present in a 0.0200 mol sample of nicotine?

Accepted Answer

The number of molecules in a mole of any substance is given by Avogadro's number, which is approximately 6.02 × 10^23 molecules/mol. Therefore, 0.0200 mol of nicotine would contain 0.0200 mol × 6.02 × 10^23 molecules/mol = 1.20 × 10^22 molecules.

Question 19

What is the mass of a 0.0200 mol sample of nicotine? [Formula mass: nicotine, 162.2 amu]

Accepted Answer

The answer of What is the mass of a 0.0200...

Question 20

How many aspirin molecules are present in a 0.325 g sample of aspirin? [Molar mass: aspirin, 180.2 g/mol]

Accepted Answer

To find the number of aspirin molecules, first calculate the number of moles of aspirin using its molar mass: $0.325 \, \text{g} \div 180.2 \, \text{g/mol} = 1.80 \times 10^{-3} \, \text{moles}$. Then, multiply by Avogadro's number ($6.022 \times 10^{23} \, \text{molecules/mole}$) to find the number of molecules: $1.80 \times 10^{-3} \, \text{moles} \times 6.022 \times 10^{23} \, \text{molecules/mole} = 1.09 \times 10^{21} \, \text{molecules}$.

Quiz 4: Calculations, Chemical Changes, and the Chemical Equation

Aspirin is the common name for acetyl salicylic acid, C₉H₈O₄.One tablet contains 0.325 g of aspirin.How many moles of aspirin is this?

Classify the following reaction: Ce⁴⁺(aq) + Fe²⁺(aq) → Ce³⁺(aq) + Fe³⁺(aq)

Methanol (CH₃OH) is the fuel used by racecars in the Indianapolis 500.It burns in the engine according to the equation below.How many moles of oxygen gas are necessary to react completely with 425 moles of methanol? 2CH₃OH(l) + 3O₂(g) → 2CO₂(g) + 4H₂O(g)

The chemical equation below is not balanced.What is the coefficient of iron when the equation is balanced with smallest whole number coefficients? Fe(s) + O₂(g) → Fe₂O₃(s)

How many moles of hydrogen gas are needed to react with oxygen to form one mole of water? 2H₂(g) + O₂(g) → 2H₂O(l)

Choose the best classification of the reaction represented by the following equation: C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H₂O(l)

Which of the choices is the correctly balanced form of the following equation? C₆H₁₄(l) + O₂(g) → CO₂(g) + H₂O(l)

Prozac, a drug prescribed to treat depression, has the formula C₁₇H₁₈F₃NO.If a patient was administered 15.0 mg of Prozac, how many moles of Prozac did he receive? [Molar mass: Prozac, 309.36 g/mol]

Consider the hypothetical reaction: 3A₂ + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B, what is the maximum amount of C that can be formed?

Consider the following precipitation reaction.Which of the following correctly identifies the spectator ions in this reaction? Na₂S(aq) + CuSO₄(aq) → Na₂SO₄(aq) + CuS(s)

What is the formula mass of carbon dioxide? [Atomic masses: C, 12.01 amu; O, 16.00 amu]

Choose the best classification of the reaction represented by the following equation: Na₂SO₄(aq) + Ba(OH) ₂(aq) → BaSO₄(s) + 2NaOH(aq)

Choose the best classification of the reaction represented by the following equation: 2KClO₃(s) → 2KCl(s) + 3O₂(g)

Classify the following reaction: H₂SO₄(aq) + 2KOH(aq) → K₂SO₄(aq) + 2H₂O(aq)

When solutions of sodium sulfide and copper(II) sulfate are mixed, a precipitate of copper(II) sulfide is formed.What is the net ionic equation for this reaction?

How many molecules are present in a 0.0200 mol sample of nicotine?

What is the mass of a 0.0200 mol sample of nicotine? [Formula mass: nicotine, 162.2 amu]

How many aspirin molecules are present in a 0.325 g sample of aspirin? [Molar mass: aspirin, 180.2 g/mol]

Quiz 4: Calculations, Chemical Changes, and the Chemical Equation

Aspirin is the common name for acetyl salicylic acid, C9H8O4.One tablet contains 0.325 g of aspirin.How many moles of aspirin is this?

Classify the following reaction: Ce4+(aq) + Fe2+(aq) → Ce3+(aq) + Fe3+(aq)

Methanol (CH3OH) is the fuel used by racecars in the Indianapolis 500.It burns in the engine according to the equation below.How many moles of oxygen gas are necessary to react completely with 425 moles of methanol? 2CH3OH(l) + 3O2(g) → 2CO2(g) + 4H2O(g)

The chemical equation below is not balanced.What is the coefficient of iron when the equation is balanced with smallest whole number coefficients? Fe(s) + O2(g) → Fe2O3(s)

How many moles of hydrogen gas are needed to react with oxygen to form one mole of water? 2H2(g) + O2(g) → 2H2O(l)

Choose the best classification of the reaction represented by the following equation: C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(l)

Which of the choices is the correctly balanced form of the following equation? C6H14(l) + O2(g) → CO2(g) + H2O(l)

Prozac, a drug prescribed to treat depression, has the formula C17H18F3NO.If a patient was administered 15.0 mg of Prozac, how many moles of Prozac did he receive? [Molar mass: Prozac, 309.36 g/mol]

Consider the hypothetical reaction: 3A2 + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B, what is the maximum amount of C that can be formed?

Consider the following precipitation reaction.Which of the following correctly identifies the spectator ions in this reaction? Na2S(aq) + CuSO4(aq) → Na2SO4(aq) + CuS(s)

What is the formula mass of carbon dioxide? [Atomic masses: C, 12.01 amu; O, 16.00 amu]

Choose the best classification of the reaction represented by the following equation: Na2SO4(aq) + Ba(OH) 2(aq) → BaSO4(s) + 2NaOH(aq)

Choose the best classification of the reaction represented by the following equation: 2KClO3(s) → 2KCl(s) + 3O2(g)

Classify the following reaction: H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + 2H2O(aq)

When solutions of sodium sulfide and copper(II) sulfate are mixed, a precipitate of copper(II) sulfide is formed.What is the net ionic equation for this reaction?

How many molecules are present in a 0.0200 mol sample of nicotine?

What is the mass of a 0.0200 mol sample of nicotine? [Formula mass: nicotine, 162.2 amu]

How many aspirin molecules are present in a 0.325 g sample of aspirin? [Molar mass: aspirin, 180.2 g/mol]

Aspirin is the common name for acetyl salicylic acid, C₉H₈O₄.One tablet contains 0.325 g of aspirin.How many moles of aspirin is this?

Classify the following reaction: Ce⁴⁺(aq) + Fe²⁺(aq) → Ce³⁺(aq) + Fe³⁺(aq)

Methanol (CH₃OH) is the fuel used by racecars in the Indianapolis 500.It burns in the engine according to the equation below.How many moles of oxygen gas are necessary to react completely with 425 moles of methanol? 2CH₃OH(l) + 3O₂(g) → 2CO₂(g) + 4H₂O(g)

The chemical equation below is not balanced.What is the coefficient of iron when the equation is balanced with smallest whole number coefficients? Fe(s) + O₂(g) → Fe₂O₃(s)

How many moles of hydrogen gas are needed to react with oxygen to form one mole of water? 2H₂(g) + O₂(g) → 2H₂O(l)

Choose the best classification of the reaction represented by the following equation: C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H₂O(l)

Which of the choices is the correctly balanced form of the following equation? C₆H₁₄(l) + O₂(g) → CO₂(g) + H₂O(l)

Prozac, a drug prescribed to treat depression, has the formula C₁₇H₁₈F₃NO.If a patient was administered 15.0 mg of Prozac, how many moles of Prozac did he receive? [Molar mass: Prozac, 309.36 g/mol]

Consider the hypothetical reaction: 3A₂ + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B, what is the maximum amount of C that can be formed?

Consider the following precipitation reaction.Which of the following correctly identifies the spectator ions in this reaction? Na₂S(aq) + CuSO₄(aq) → Na₂SO₄(aq) + CuS(s)

Choose the best classification of the reaction represented by the following equation: Na₂SO₄(aq) + Ba(OH) ₂(aq) → BaSO₄(s) + 2NaOH(aq)

Choose the best classification of the reaction represented by the following equation: 2KClO₃(s) → 2KCl(s) + 3O₂(g)

Classify the following reaction: H₂SO₄(aq) + 2KOH(aq) → K₂SO₄(aq) + 2H₂O(aq)