Ch 7 Stoichiometry Test

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

• Write a Balanced Equation
• Panic
• Write an Unbalanced Equation
• Ask for help

 The equation for Percent Yield:

• (predicted/experimental) X 100
• (experimental/predicted) X 100
• (experimental - predicted)/ Predicted X 100

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

What is a Limiting Reagent?

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

What is a Excess Reagent?

• amount you end with
• what you run out of first
• what you have left over
• what you start with

You need 2 pieces of bread, 1 tablespoon of peanut butter and 2 tablespoons of jelly to make a sandwich.  If you have 10 pieces of bread, 4 tablespoons of peanut butter and 20 tablespoons of jelly, what is the limiting reactant?

• bread
• jelly
• peanut butter
• sandwich

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

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

The Formula to make S'mores is:
2C + 1M + G₂ → C₂MG₂. If you have 5 Marshmallows (M), 9 Chocolate Pieces (C), and 9 Graham Cracker Halves (G), how many S'mores can you make?

• 5
• 4
• 8
• 42

What is the molar mass of C₆H₁₂O₆?

• 180.18
• 180.12
• 180.24
• 180.06

 CaC₂(s) + 2H₂O(l)   -->   C₂H₂(g)   + Ca(OH)₂(aq)
how many grams of Ca(OH)₂ would be formed with 3.20 moles of CaC₂?

• 119 g
• 21.2 g
• 114 g
• 237 g