Answer : The percent yield of
is, 87.88%
Solution :
First we have to calculate the moles of
and
.


Now we have to calculate the limiting and excess reagent.
The balanced chemical reaction is,

From the balanced reaction we conclude that
As, 2 moles of
react with 1 mole of 
So, 5.5 moles of
react with
moles of 
That means, in the given balanced reaction,
is a limiting reagent because it limits the formation of products and
is an excess reagent.
The excess reagent remains
= 2.9 - 2.75 = 0.15 moles
Now we have to calculate the moles of
.
As, 2 moles of
react with 2 moles of 
As, 5.5 moles of
react with 5.5 moles of 
Now we have to calculate the mass of
.


Therefore, the mass water produces, 99 g
Now we have to calculate the percent yield of
.

Therefore, the percent yield of
is, 87.88%