Reacting 953 mol of SiO2 with excess carbon yields 29.6 kg of SiC. What is the percentage yield?

Question

This is copied and pasted from my homework. But 953 moles seems insane to me. I've tried this problem and can't get it right. Please help! 

Answer 1

First we need the balanced chemical equation:

 

  SiO₂ +   C  ------>   SiC + O₂

 

Then we calculate how much SiC should be produced from 953 moles of SiO_2.  Since the ratio is 1 to 1, we will produce 953 moles of SiC.  953 moles of SiC weighs [28.086 (Si) + 12.011 (C)]*953 /1000 m(g to kg) = 38.2 Kg.

 

The percentage yield is 29.6/38.2 * 100 = 77.5%