Calcium carbide is made in an electric furnace according to the
following equation: CaO + 3C ---->CaC2 + CO. According to mass-mass
calculations, 75.5 kg of CaO will produce 85.9 kg of calcium carbide.
If the percentage yield of the process is 92.4%, how much calcium
carbide will be produced?
a. 69.8 kg
b. 149 kg
c. 75.5 kg
d. 79.4 kg

Hi Teate,
   
Answer is d. 79.4 kg
  
Calculation:
100% yield is equivalent to 85.9 kg of Calcium Carbide
1% yield is equivalent to (85.9/100kg) 0.859kg of Calcium Carbide
92.4% yield is equivalent to (0.859X92.4kg) 79.3716 kg of Calcium Carbide
Answer is 79.4 kg (accurate to 1 decimal place)
  
I hope this helps!