Answer : The theoretical yield of potassium carbonate is, 146.483 g
The percent yield of potassium carbonate is, 85.33 %
Solution : Given,
Mass of
= 150 g
Mass of
= 90 g
Molar mass of
= 212.27 g/mole
Molar mass of
= 233.99 g/mole
Molar mass of
= 138.205 g/mole
First we have to calculate the moles of
and 


The given balanced reaction is,

From the given reaction, we conclude that
2 moles of
react with 1 mole of 
0.7066 moles of
react with
moles of 
But the moles of
is, 0.3846 moles.
So,
is an excess reagent and
is a limiting reagent.
Now we have to calculate the moles of
.
As, 2 moles of
react to give 3 moles of 
So, 0.7066 moles of
react to give
moles of 
Now we have to calculate the mass of
.


The theoretical yield of potassium carbonate = 146.483 g
The experimental yield of potassium carbonate = 125 g
Now we have to calculate the % yield of potassium carbonate.
Formula for percent yield :


Therefore, the % yield of potassium carbonate is, 85.33%