RPAL Theoretical Yield 2

Question 1

What assumption underlies the theoretical yield calculation?

Accepted Answer

The reaction proceeds to completion with 100% conversion of limiting reagent to product

Answer

Theoretical yield assumes all of the limiting reagent is converted to product with no side reactions or losses.

Question 2

In 2C + O₂ → 2CO, if 4 mol C and 1 mol O₂ react, what is the theoretical yield of CO?

Accepted Answer

2 mol CO

Answer

O₂ is limiting (1 mol O₂ for 2 mol C needed, but 4 mol C present); 1 mol O₂ produces 2 mol CO from the 1:2 ratio.

Question 3

A student calculates a theoretical yield of 8.5 g for a product with a molar mass of 17 g/mol. How many moles of product does this represent?

Accepted Answer

0.5 mol

Answer

8.5 g ÷ 17 g/mol = 0.5 mol of product.

Question 4

Which of the following would NOT change the theoretical yield?

Accepted Answer

Adding more excess reagent

Answer

Adding more of the excess reagent does not increase theoretical yield because the limiting reagent still controls product formation.

Question 5

For CaCO₃ → CaO + CO₂, if 100 g of CaCO₃ (molar mass = 100 g/mol) reacts completely, what is the theoretical yield of CO₂ (molar mass = 44 g/mol)?

Accepted Answer

44 g

Answer

100 g CaCO₃ = 1 mol; the 1:1 ratio gives 1 mol CO₂; 1 mol × 44 g/mol = 44 g CO₂.

RPAL - Reactants, Products, and Leftovers Practice Test