Exam Review #4

If a chemist calculates the maximum amount of product that could be obtained in a chemical reaction, he or she is calculating the

• theoretical yield

• mole ratio

• actual yield

• percentage yield

What is the measured amount of a product obtained from a chemical reaction?

• mole ratio

• theoretical yield

• percentage yield

• actual yield

Mole ratios are obtained from the

• balanced chemical equation

• periodic table

• molar mass

What is the mole ratio of H₂O to H₃PO₄ in the following chemical equation?   P₄O₁₀ + 6 H₂O --> 4 H₃PO₄ 

• 6:4

• 4:6

• 1:3

• 3:1

For the reaction represented by the equation Cl₂ + 2KBr → Br₂ + 2KCl, how many grams of potassium chloride can be produced from 356 grams potassium bromide?

• 749 g

• 225 g

• 479 g

• 814 g

Using the following equation:
Fe₂O₃(s) + 3H₂(g) → 2Fe(s) + 3H₂O(l)
How many moles of iron can be made from  6 moles H₂? 

• 4 moles Fe

• 6 moles Fe

• 9 moles Fe

• 2 moles Fe

9. Complete the equation for the percent yield of a chemical reaction:
Percent yield=(________)÷(________)×100%

• actual yield; theoretical yield

• theoretical yield; actual yield

Every type of stoichiometry problem requires the use of

• bond energies

• lewis structures

• molar mass

• mole ratios

What is the molar mass of oxygen gas?

• 16 g/mol

• 32 g/mol

• 8 g/mol

If an experiment gives a percent yield of 104%, which is the most likely source of error?

• precipitate was lost

• the precipitate is still wet

• all of the reactants did not react

• the filter paper has a hole in it