Mole Ratio Problems

What is a mole ratio?

• An animal that burrows underground.

• How many moles of reactant are used up in a chemical reaction.

• The ratio of a reactant / product to a different one - compared by the number of particles.

• The process by which we multiply fractions by using numbers from a chemistry problem.

Tags

NGSS.HS-PS1-7

Where are the numbers for a mole ratio found?

• They are part of the chemical formulas for the reactants / products.

• They are given in the problem.

• They are found on the periodic table for those elements.

• They are found as coefficients in the reaction's balanced chemical equation.

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O

Ethane (C₂H₆) combusts in the above reaction. What is the mole ratio of ethane to oxygen gas?

• 
• 
• 
• 

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O

Ethane (C₂H₆) combusts in the above reaction. What is the mole ratio of carbon dioxide to water?

• 
• 
• 
• 

Tags

NGSS.HS-PS1-7

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O

A problem asks how many moles of oxygen gas are needed to react completely with 6 moles of ethane (C₂H₆). What is the first step in setting up the problem?

• 
• 
• 
• 

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O

A problem asks how many moles of oxygen gas are needed to react completely with 6 moles of ethane (C₂H₆). What is the second step in setting up the problem?

• 
• 
• 
• 

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O

A problem asks how many moles of oxygen gas are needed to react completely with 6 moles of ethane (C₂H₆). What is the final answer for this problem?

• 13 mol C₂H₆

• 3 mol O₂

• 21 mol O₂

• 42 mol O₂

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O

New problem: If 16 moles of carbon dioxide are formed by this reaction, how many moles of water were also produced?

• 4 mol H₂O

• 6 mol H₂O

• 24 mol H₂O

• 96 mol H₂O

• 384 mol H₂O

Tags

NGSS.HS-PS1-7

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O

New problem: If 3.5 moles of oxygen gas are used up as ethane combusts completely, how many moles of carbon dioxide are produced?

• 0.5 mol CO₂

• 0.57 mol CO₂

• 2.0 mol CO₂

• 3.0 mol CO₂

• 3.5 mol CO₂

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O

New problem: How many moles of ethane (C₂H₆) are required to produce 13.5 moles of water from the above reaction?

• 4.5 mol C₂H₆

• 27 mol C₂H₆

• 40.5 mol C₂H₆

• 81 mol C₂H₆

• 162 mol C₂H₆

Tags

NGSS.HS-PS1-7