Percentage Yield (chemistry Only) (GCSE Chemistry)

When calculating theoretical yield you must base the calculation on the limiting reagent. Which statement is correct?

If theoretical yield is based on limiting reagent but the student used excess of the other reagent, what happens to theoretical yield?

A student makes a salt and gets a measured mass higher than expected. Which lab error would cause an erroneously low calculated percentage yield (i.e., you think yield smaller than it really is)?

When calculating percentage yield using masses, why must you convert masses to moles if reaction equation involves mole ratios?

A theoretical yield requires calculations using balanced equation. For 2A + 3B ? 4C, if you start with 0.500 mol A and excess B, how many moles of C are theoretically possible?

A chemist reports a percentage yield of 0% for a reaction. Which is the most likely interpretation?

A student planned to make 0.250 mol of product but actually obtained 0.160 mol. What is percentage yield?

Which of these reasons explains a low percentage yield (e.g., 45%)?

A reaction produces theoretical gaseous product volume 24.0 dm3 but measured collection is 19.2 dm3. What is percentage yield?

Calcium carbonate is heated to give calcium oxide. Theoretical mass of CaO = 12.0 g but student obtains 10.0 g. What is the percentage yield (to 3 s.f.)?

You obtain 2.40 g product but after drying it still contains 0.10 g solvent. The theoretical mass is 2.50 g. Which is the correct percentage yield (use dry mass)?