Stoichiometry

2H₂  +   O₂  →  2H₂O How many moles of O₂ are consumed if 8 moles H₂ are used?

• 2
• 4
• 6
• 8

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

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

• 1 mol MgO/ 2 mol Fe

• 3 mol MgO / 2 mol Fe

2Na + 2H₂O → 2NaOH+ H₂ How many grams of H₂ are produced if 120 g of Na are available?

• 5.2 g
• 2.6 g
• 690 g
• 45 g

CH₄ + 2 O₂ → CO₂ + 2 H₂O How many moles of CO₂ are produced from the combustion of 110 g of CH₄?

• 13.7 mol
• 2.75 mol
• 6.11 mol
• 6.85 mol

2 NaClO₃ (s) --> 2NaCl (s) +3 O₂ (g)  
12.00 moles of NaClO₃ will produce how many grams of O₂?

• 256 g of O₂
• 576 g of O₂
• 288 g O₂

B₂H₆ + 3O₂ -->2 HBO₂ + 2 H₂O
 What mass of O₂ will be needed to burn 36.1 g of B₂H₆?

• 13.8 g O₂
• 3.86 mol of O₂
• 124 g O₂

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

• Write your given Number, Unit, Substance

• Write your given Number and Unit

• Write your given Number

• Put numbers into your fraction

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

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

 The equation for Percent Yield:

• (theoretical/actual) X 100

• (actual/theoretical) X 100

• (limiting/excess)/ X 100

What is a Limiting Reactant?

• speeds up a reaction
• what you run out of first
• what you have left over
• slows down a reaction