Question

If 0.83 moles of carbon monoxide gas are produced by the following reaction, how many grams of silicon dioxide and of carbon were reacted (assume just enough of each)?

SiO₂(s) + 2 C(s) → Si(l) + 2CO(g)

Answer 1

1)

From reaction,

mol of SiO2 reacted = (1/2)*moles of CO formed

= (1/2)*0.83 mol

= 0.415 mol

Molar mass of SiO2,

MM = 1*MM(Si) + 2*MM(O)

= 1*28.09 + 2*16.0

= 60.09 g/mol

use:

mass of SiO2,

m = number of mol * molar mass

= 0.415 mol * 60.09 g/mol

= 24.94 g

Answer: 25 g

2)

From reaction,

mol of C reacted = (1/1)*moles of CO formed

= 0.83 mol

Molar mass of C = 12.01 g/mol

use:

mass of C,

m = number of mol * molar mass

= 0.83 mol * 12.01 g/mol

= 9.97 g

Answer: 10. g