C is the correct answer because density is mass per unit volume and when you divide it we that volume is greater than mass so density is less density density is directly proportional to Mass Density is inversely proportional to volume
I assume you’re looking for a balanced equation.
SiCl4 + 2H2O = SiO2 + 4HCl
Answer : The mass defect required to release energy is 6111.111 kg
Explanation :
To calculate the mass defect for given energy released, we use Einstein's equation:

E = Energy released = 
= mass change = ?
c = speed of light = 
Now put all the given values in above equation, we get:


Therefore, the mass defect required to release energy is 6111.111 kg