Question 1

When the following equation is balanced, the coefficient of C₃H₈O₃ is ________. C₃H₈O₃ (g) + O₂(g) → CO₂ (g) + H₂O (g) A)1 B)2 C)3 D)7 E)5

Accepted Answer

The equation is already balanced except for the coefficient of C₃H₈O₃. This compound contains one carbon, two sulfur, 18 hydrogen, and 13 oxygen atoms. To balance the equation, we need two of this compound on the left side, which gives a coefficient of 2 for C₃H₈O₃. Thus, the coefficient of this compound is 2.

Question 2

When the following equation is balanced, the coefficient of water is ________. K (s) + H₂O (l) → KOH (aq) + H₂ (g) A)1 B)2 C)3 D)4 E)5

Accepted Answer

The answer of When the following equation is balanced, the...

Question 3

When the following equation is balanced, the coefficient of O₂ is ________. C₂H₄O (g) + O₂ (g) → CO₂ (g) + H₂O (g) A)2 B)3 C)4 D)5 E)1

Accepted Answer

The answer of When the following equation is balanced, the...

Question 4

There are ________ mol of carbon atoms in 4 mol of C₄H₈O₂. A)4 B)8 C)16 D)20 E)32

Accepted Answer

The molecular formula given contains 32 carbon atoms in total (1 carbon in C₄H₈O and 12 carbons in ₂). Therefore, 4 mol of this compound contains 4 mol x 32 mol of carbon/mol = 128 mol of carbon. Since there are 8 mol of carbon in 0.5 mol C₆, there must be 16 mol of carbon in 1 mol C₆. Thus, 128 mol of carbon is equivalent to 128 mol / 16 mol C₆/mol = 8 mol of C₆. Therefore, there are 16 mol of carbon atoms in 4 mol of C₄H₈O₂.

Question 5

When the following equation is balanced, the coefficient of oxygen is ________. PbS (s) + O₂ (g) → PbO (s)+ SO₂ (g) A)1 B)3 C)2 D)4 E)5

Accepted Answer

The answer of When the following equation is balanced, the...

Question 6

Write the balanced equation for the reaction that occurs when methanol, CH₃OH (l), is burned in air. What is the coefficient of oxygen in the balanced equation? A)1 B)2 C)3 D)4 E)3/2

Accepted Answer

The balanced equation for the combustion of methanol is 2 CH₃OH + 3 O₂ → 2 CO₂ + 4 H₂O. The coefficient of oxygen (O₂) is 3.

Question 7

The balanced equation for the decomposition of sodium azide is ________. A)2NaN₃ (s) → 2Na (s) + 3N₂ (g) B)2NaN₃ (s) → Na₂ (s) + 3N₂ (g) C)NaN₃ (s) → Na (s) + N₂ (g) D)NaN₃ (s) → Na (s) + N₂ (g) + N (g) E)2NaN₃ (s) → 2Na (s) + 2N₂ (g)

Accepted Answer

The correct balanced equation for the decomposition of sodium azide (NaN3) is 2NaN3 (s) → 2Na (s) + 3N2 (g), which matches choice A when the subscript formatting is corrected.

Question 8

When the following equation is balanced, the coefficient of HNO₃ is ________. HNO₃ (aq) + CaCO₃ (s) → Ca(NO₃)₂ (aq) + CO₂ (g) + H₂O (l) A)1 B)2 C)3 D)5 E)4

Accepted Answer

The balanced equation is: 2 HNO₃(aq) + CaCO₃(s) → Ca(NO₃)₂(aq) + CO₂(g) + 2 H₂O(l) Therefore, the coefficient of HNO₃ is 2.

Question 9

Predict the product in the combination reaction below. Al (s) + N₂ (g) → ________ A)AlN B)Al₃N C)AlN₂ D)Al₃N₂ E)AlN₃

Accepted Answer

This is a combination reaction between aluminum (Al) and nitrogen gas (N2) which forms aluminum nitride (AlN) according to the following balanced chemical equation: 2Al (s) + N2 (g) → 2AlN (s). The compound in the question, N₂, is not a valid chemical formula.

Question 10

When the following equation is balanced, the coefficient of H₂ is ________. CO (g) + H₂ (g) → H₂O (g) + CH₄ (g) A)1 B)2 C)3 D)4 E)0

Accepted Answer

The answer of When the following equation is balanced, the...

Question 11

When the following equation is balanced, the coefficient of water is ________. N₂O₅ (g) + H₂O (l) → HNO₃ (aq) A)5 B)2 C)3 D)4 E)1

Accepted Answer

The answer of When the following equation is balanced, the...

Question 12

When the following equation is balanced, the coefficient of nitric acid is ________. N₂O₅ (g) + H₂O (l) → HNO₃ (aq) A)5 B)2 C)3 D)4 E)1

Accepted Answer

The balanced equation is N2O5 + H2O → 2 HNO3, so the coefficient of nitric acid is 2.

Question 13

Write the balanced equation for the reaction that occurs when methanol, CH₃OH (l), is burned in air. What is the coefficient of methanol in the balanced equation? A)1 B)2 C)3 D)4 E)3/2

Accepted Answer

The answer of Write the balanced equation for the reaction...

Question 14

When the following equation is balanced, the coefficient of hydrogen is ________. K (s) + H₂O (l) → KOH (aq) + H₂ (g) A)1 B)2 C)3 D)4 E)5

Accepted Answer

The answer of When the following equation is balanced, the...

Question 15

When the following equation is balanced, the coefficient of H₃PO₄ is ________. H₃PO₄ (aq) + NaOH (aq) → Na₃PO₄ (aq) + H₂O (l) A)1 B)2 C)3 D)4 E)0

Accepted Answer

The equation is already balanced as written, with all elements having the same number of atoms on both sides of the equation.

Question 16

When the following equation is balanced, the coefficient of H₂SO₄ is ________. H₂SO₄ (aq) + NaOH (aq) → Na₂SO₄ (aq) + H₂O (l) A)1 B)2 C)3 D)4 E)0.5

Accepted Answer

The equation is already balanced as written, with all elements having the same number of atoms on both sides of the equation. Therefore, the coefficient of $HSO_4^-$ is 1.

Question 17

When the following equation is balanced, the coefficient of HCl is ________. CaCO₃ (s) + HCl (aq) → CaCl₂ (aq) + CO₂ (g) + H₂O (l) A)1 B)2 C)3 D)4 E)0

Accepted Answer

To balance the equation, you need two HCl molecules on the left side to react with the CaCO3.

Question 18

What is the coefficient of O₂ when the following equation is completed and balanced? C₄H₈O₂ + O₂ → ________ A)2 B)3 C)5 D)6 E)1

Accepted Answer

The answer of What is the coefficient of O₂ when...

Question 19

When the following equation is balanced, the coefficient of sulfur dioxide is ________. PbS (s) + O₂ (g) → PbO (s) + SO₂ (g) A)5 B)1 C)3 D)2 E)4

Accepted Answer

The balanced equation is PbS + 2O2 → PbO + SO2, so the coefficient of sulfur dioxide (SO2) is 2.

Question 20

When the following equation is balanced, the coefficient of dinitrogen pentoxide is ________. N₂O₅ (g) + H₂O (l) → HNO₃ (aq) A)1 B)2 C)3 D)4 E)5

Accepted Answer

The balanced chemical equation is N2O5(g) + H2O(l) → 2HNO3(aq), which means the coefficient of dinitrogen pentoxide (N2O5) is 1.

Quiz 3: Stoichiometry: Calculations With Chemical Formulas and Equations

When the following equation is balanced, the coefficient of C₃H₈O₃ is ________. C₃H₈O₃ (g) + O₂(g) → CO₂ (g) + H₂O (g)

When the following equation is balanced, the coefficient of water is ________. K (s) + H₂O (l) → KOH (aq) + H₂ (g)

When the following equation is balanced, the coefficient of O₂ is ________. C₂H₄O (g) + O₂ (g) → CO₂ (g) + H₂O (g)

There are ________ mol of carbon atoms in 4 mol of C₄H₈O₂.

When the following equation is balanced, the coefficient of oxygen is ________. PbS (s) + O₂ (g) → PbO (s) + SO₂ (g)

Write the balanced equation for the reaction that occurs when methanol, CH₃OH (l) , is burned in air. What is the coefficient of oxygen in the balanced equation?

The balanced equation for the decomposition of sodium azide is ________.

When the following equation is balanced, the coefficient of HNO₃ is ________. HNO₃ (aq) + CaCO₃ (s) → Ca(NO₃) ₂ (aq) + CO₂ (g) + H₂O (l)

Predict the product in the combination reaction below. Al (s) + N₂ (g) → ________

When the following equation is balanced, the coefficient of H₂ is ________. CO (g) + H₂ (g) → H₂O (g) + CH₄ (g)

When the following equation is balanced, the coefficient of water is ________. N₂O₅ (g) + H₂O (l) → HNO₃ (aq)

When the following equation is balanced, the coefficient of nitric acid is ________. N₂O₅ (g) + H₂O (l) → HNO₃ (aq)

Write the balanced equation for the reaction that occurs when methanol, CH₃OH (l) , is burned in air. What is the coefficient of methanol in the balanced equation?

When the following equation is balanced, the coefficient of hydrogen is ________. K (s) + H₂O (l) → KOH (aq) + H₂ (g)

When the following equation is balanced, the coefficient of H₃PO₄ is ________. H₃PO₄ (aq) + NaOH (aq) → Na₃PO₄ (aq) + H₂O (l)

When the following equation is balanced, the coefficient of H₂SO₄ is ________. H₂SO₄ (aq) + NaOH (aq) → Na₂SO₄ (aq) + H₂O (l)

When the following equation is balanced, the coefficient of HCl is ________. CaCO₃ (s) + HCl (aq) → CaCl₂ (aq) + CO₂ (g) + H₂O (l)

What is the coefficient of O₂ when the following equation is completed and balanced? C₄H₈O₂ + O₂ → ________

When the following equation is balanced, the coefficient of sulfur dioxide is ________. PbS (s) + O₂ (g) → PbO (s) + SO₂ (g)

When the following equation is balanced, the coefficient of dinitrogen pentoxide is ________. N₂O₅ (g) + H₂O (l) → HNO₃ (aq)

Quiz 3: Stoichiometry: Calculations With Chemical Formulas and Equations

When the following equation is balanced, the coefficient of C3H8O3 is ________. C3H8O3 (g) + O2 (g) → CO2 (g) + H2O (g)

When the following equation is balanced, the coefficient of water is ________. K (s) + H2O (l) → KOH (aq) + H2 (g)

When the following equation is balanced, the coefficient of O2 is ________. C2H4O (g) + O2 (g) → CO2 (g) + H2O (g)

There are ________ mol of carbon atoms in 4 mol of C4H8O2.

When the following equation is balanced, the coefficient of oxygen is ________. PbS (s) + O2 (g) → PbO (s) + SO2 (g)

Write the balanced equation for the reaction that occurs when methanol, CH3OH (l) , is burned in air. What is the coefficient of oxygen in the balanced equation?

The balanced equation for the decomposition of sodium azide is ________.

When the following equation is balanced, the coefficient of HNO3 is ________. HNO3 (aq) + CaCO3 (s) → Ca(NO3) 2 (aq) + CO2 (g) + H2O (l)

Predict the product in the combination reaction below. Al (s) + N2 (g) → ________

When the following equation is balanced, the coefficient of H2 is ________. CO (g) + H2 (g) → H2O (g) + CH4 (g)

When the following equation is balanced, the coefficient of water is ________. N2O5 (g) + H2O (l) → HNO3 (aq)

When the following equation is balanced, the coefficient of nitric acid is ________. N2O5 (g) + H2O (l) → HNO3 (aq)

Write the balanced equation for the reaction that occurs when methanol, CH3OH (l) , is burned in air. What is the coefficient of methanol in the balanced equation?

When the following equation is balanced, the coefficient of hydrogen is ________. K (s) + H2O (l) → KOH (aq) + H2 (g)

When the following equation is balanced, the coefficient of H3PO4 is ________. H3PO4 (aq) + NaOH (aq) → Na3PO4 (aq) + H2O (l)

When the following equation is balanced, the coefficient of H2SO4 is ________. H2SO4 (aq) + NaOH (aq) → Na2SO4 (aq) + H2O (l)

When the following equation is balanced, the coefficient of HCl is ________. CaCO3 (s) + HCl (aq) → CaCl2 (aq) + CO2 (g) + H2O (l)

What is the coefficient of O2 when the following equation is completed and balanced? C4H8O2 + O2 → ________

When the following equation is balanced, the coefficient of sulfur dioxide is ________. PbS (s) + O2 (g) → PbO (s) + SO2 (g)

When the following equation is balanced, the coefficient of dinitrogen pentoxide is ________. N2O5 (g) + H2O (l) → HNO3 (aq)

When the following equation is balanced, the coefficient of C₃H₈O₃ is ________. C₃H₈O₃ (g) + O₂(g) → CO₂ (g) + H₂O (g)

When the following equation is balanced, the coefficient of water is ________. K (s) + H₂O (l) → KOH (aq) + H₂ (g)

When the following equation is balanced, the coefficient of O₂ is ________. C₂H₄O (g) + O₂ (g) → CO₂ (g) + H₂O (g)

There are ________ mol of carbon atoms in 4 mol of C₄H₈O₂.

When the following equation is balanced, the coefficient of oxygen is ________. PbS (s) + O₂ (g) → PbO (s) + SO₂ (g)

Write the balanced equation for the reaction that occurs when methanol, CH₃OH (l) , is burned in air. What is the coefficient of oxygen in the balanced equation?

When the following equation is balanced, the coefficient of HNO₃ is ________. HNO₃ (aq) + CaCO₃ (s) → Ca(NO₃) ₂ (aq) + CO₂ (g) + H₂O (l)

Predict the product in the combination reaction below. Al (s) + N₂ (g) → ________

When the following equation is balanced, the coefficient of H₂ is ________. CO (g) + H₂ (g) → H₂O (g) + CH₄ (g)

When the following equation is balanced, the coefficient of water is ________. N₂O₅ (g) + H₂O (l) → HNO₃ (aq)

When the following equation is balanced, the coefficient of nitric acid is ________. N₂O₅ (g) + H₂O (l) → HNO₃ (aq)

Write the balanced equation for the reaction that occurs when methanol, CH₃OH (l) , is burned in air. What is the coefficient of methanol in the balanced equation?

When the following equation is balanced, the coefficient of hydrogen is ________. K (s) + H₂O (l) → KOH (aq) + H₂ (g)

When the following equation is balanced, the coefficient of H₃PO₄ is ________. H₃PO₄ (aq) + NaOH (aq) → Na₃PO₄ (aq) + H₂O (l)

When the following equation is balanced, the coefficient of H₂SO₄ is ________. H₂SO₄ (aq) + NaOH (aq) → Na₂SO₄ (aq) + H₂O (l)

When the following equation is balanced, the coefficient of HCl is ________. CaCO₃ (s) + HCl (aq) → CaCl₂ (aq) + CO₂ (g) + H₂O (l)

What is the coefficient of O₂ when the following equation is completed and balanced? C₄H₈O₂ + O₂ → ________

When the following equation is balanced, the coefficient of sulfur dioxide is ________. PbS (s) + O₂ (g) → PbO (s) + SO₂ (g)

When the following equation is balanced, the coefficient of dinitrogen pentoxide is ________. N₂O₅ (g) + H₂O (l) → HNO₃ (aq)