Mixed Stoichiometry Problems

Nitric acid is formed by the reaction of nitrogen dioxide with water:

NO_{2 (g)} + H₂O _(l) → NO _(g) + HNO_{3 (aq)}

How many moles of water are needed to react with 8.4 mol NO₂?

• 2.8 mol H₂O

• 3.0 mol H₂O

• 8.4 mol H₂O

• 25 mol H₂O

Phosphorus trifluoride is formed from its elements:

P_{4 (s)} + F_{2 (g)} → PF_{3 (g)}

How many grams of fluorine are needed to react with 6.20 g of phosphorus?

• 2.85 g F₂

• 5.70 g F₂

• 11.4 g F₂

• 37.2 g F₂

True or False

A mole ratio is always written with the larger number in the denominator.

• Never

• Sometimes

• True

• False

Every stoichiometric calculation uses a balanced chemical equation.

• Never

• Sometimes

• True

• False

Tags

NGSS.HS-PS1-7

What volume of H₂ can be prepared from the reaction of 3.27 g of zinc:

Zn + HCl → ZnCl₂ + H₂

• 1.12 L H₂

• 2.24 L H₂

• 1.64 L H₂

• 0.56 L H₂

Given the reaction:

SO_{2 (g)} + O_{2 (g)} → SO_{3 (g)}

What is the total number of liters of SO₃ produced when 32.0 L of SO₂ reacts completely?

• 11.2 L

• 32.0 L

• 40.0 L

• 44.8 L

What is the total number of moles of water needed to make 2.5 moles of C₆H₁₂O₆?

CO₂ + H₂O → C₆H₁₂O₆ + O₂

• 2.5

• 6.0

• 12

• 15

Tags

NGSS.HS-PS1-7

How many grams of C₅H₈ form from 5.45 moles of C₅H₁₂?

C₅H₁₂ → C₅H₈ + H₂

• 123 g C₅H₈

• 246 g C₅H₈

• 371 g C₅H₈

• 186 g C₅H₈

When given the equation:

KClO₃ → KCl + O₂

identify the correct mole ratio(s).

• 2 mol KClO₃/ 3 mol O₂

• 1 mol KClO₃/ 3 mol O₂

• 2 mol KCl/ 2 mol KClO₃

• 3 mol O₂/ 2 mol KClO₃

Tags

NGSS.HS-PS1-7

What volume of oxygen is produced when 75.00 g of water is decomposed by electrolysis?

H₂O → H₂ + O₂

• 23.3 L O₂

• 37.5 L O₂

• 46.6 L O₂

• 75.0 L O₂