Question

Silicon carbide, SiC, is made by heating solid carbon in the presence of silicon dioxide gas, (SiO2). Carbon monoxide is the side product of the reaction.

Calculate the mass(in gram) of SiC formed when 3.00 g of SiO2 is allowed to react with 4.50 g of carbon.

Answer 1

2C + SiO₂ = SiC + 2CO

n (SiC) = n (SiO₂) = 2 x n (C)

n = m / M

M (C) = 12 g/mol

M (SiO₂) = 60.08 g/mol

M (SiC) = 40.11 g/mol

n (C) = 4.50 / 12 = 0.375 mol

n (SiO₂) = 3.0 / 60.08 = 0.05 mol

SiO₂ is the limiting reactant. Therefore:

n (SiC) = 2 x n (SiO₂) = 2 x 0.05 = 0.1 mol

m (SiC) = n x M = 0.1 x 40.11 = 4.01 g