Three Step Stoichiometry

Stoichiometry seeks to answer the question:

• Why?
• How much?
• What type?
• When?

N₂ + 3H₂ → 2NH₃

How many moles of hydrogen (H₂) are needed to react with 2 moles of nitrogen (N₂)?

• 6

• 2

• 3

• 1

2H₂   +   O₂  →  2H₂O
How many moles of water can be produced if 8 moles H₂ are used?

• 4 moles
• 8 moles
• 16 moles
• 2 moles

Tags

NGSS.HS-PS1-7

What is the first thing you must do to solve a stoichiometry problem?

• Write a balanced equation
• Panic
• Convert grams to moles
• Use Avogadro's number

In the reaction 2 H₂ + O₂ → 2 H₂O what is the mole ratio of oxygen to water?

• 1:2
• 2:1
• 3:4
• 4:3

For the Balanced Reaction:
3 Mg + 1 Fe₂O₃ → 3 MgO + 2 Fe
What is the Ratio of moles of MgO to moles Fe? (Just be careful re: the chemicals)

• 3mol Mg / 2 mol Fe
• 2 mol Mg/ 3 mol Fe
• 1 mol Fe/ 2 mol Fe
• 3 mol MgO / 2 mol Fe

Tags

NGSS.HS-PS1-7

For the Balanced Reaction:
3 Mg + 1 Fe₂O₃ → 3 MgO + 2 Fe
 What is the Ratio of moles of Fe₂O₃ to moles Fe?

• 3mol Mg / 2 mol Fe
• 2 mol Mg/ 3 mol Fe
• 1 mol Fe₂O₃/ 2 mol Fe
• 3 mol MgO / 2 mol Fe

Tags

NGSS.HS-PS1-7

Given the equation:
2NaClO₃ (s) → 2NaCl (s) + 3O₂ (g) 
 
2.00 moles of NaClO₃ will produce how many grams of O₂? (mass of O₂ = 32g/mol)

• 56 g of O₂
• 96 g of O₂
• 64 g O₂

What is the mass of 2 moles of propane (C₃H₈)? (C=12 g/mol; H = 1 g/mol)

• 44 g

• 88 g

• 22 g

• 13 g

KNO₃ --> KNO₂ + O₂
What coefficients are needed to balance the reaction?

• 2, 2, 1
• 2, 3, 2
• 1, 2, 2
• 1, 3, 1

Tags

NGSS.HS-PS1-7