Question

Given the following reaction: Na2SO4(s) + 2 C(s) → Na2S(s) + 2 CO2(g) How many grams of carbon are required to produce 18.4 g Na2S?

Answer 1

Molar mass of Na2S = 2*MM(Na) + 1*MM(S)

= 2*22.99 + 1*32.07

= 78.05 g/mol

mass of Na2S = 18.4 g

mol of Na2S = (mass)/(molar mass)

= 18.4/78.05

= 0.2357 mol

we have the Balanced chemical equation as:

Na2SO4(s) + 2 C(s) → Na2S(s) + 2 CO2(g)

From balanced chemical reaction, we see that

when 1 mol of Na2S is produced, 2 mol of C is reacted

mol of C reacts = (2/1)* moles of Na2S

= (2/1)*0.2357

= 0.4715 mol

Molar mass of C = 12.01 g/mol

mass of C = number of mol * molar mass

= 0.4715*12.01

= 5.66 g

Answer: 5.66 g