CHM 2045C        Sample M-5 Exam   Name:____________

Module 5 Part 0: Mixture Problem    4 points

 

A mixture of NaHCO3 and Na2CO3 weighed 1.0235 g. The dissolved mixture was reacted with excess Ba(OH)2 to form 2.1028 g of BaCO3 by the following reaction:

 

Na2CO3       +       Ba(OH)2       à       BaCO3      +      2 NaOH

 

NaHCO3      +      Ba(OH)2       à       BaCO3      +       NaOH       + H2O

 

What was the percentage of NaHCO3 in the original mixture?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ANSWER: 39.5% NaHCO3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Answer:  39.51 % NaHCO3