Answer to Question #261011 in General Chemistry for Rine

Question

Nitrogen gas can be prepared by passing gaseous ammonia over solid copper(II) oxide at high temperatures. The other products of the reaction are solid copper and water vapor. If a sample containing 18.1 g of NH3 is reacted with 90.4 g of CuO. 
a. Which is the limiting reactant? 
b. How many grams of N2 will be formed?
c. If only 8.2 grams of N2 are actually formed during the experiment, what is the percent yield?

Answer 1

The equation for the reaction is

3CuO+2NH3----3Cu+N2+3H2O

A)If 240g of CuO reacts with 34g of NH3

90.4g - - - - - - - - - - - - - - - - Xg of NH3

X=12.81g .Since 12.84 is less than 18.1,

Therefore CuO is the limiting reagent.

B)If 240g of CuO produces 28g of N2

Then 90.4g ------------------------- Xg of N2

X=10.55g

C)percentage yield =(8.2/10.55)×100

=77.7%