Question

How much heat is absorbed in the complete reaction of 3.00 grams of SiO2 with excess carbon in the reaction SiO2(g) + 3C(s) → SiC(s) + 2CO(g) ΔH° = 624.7 kJ/mol?

Answer 1

Answer:

31.24 kJ

Explanation:

• SiO₂(g) + 3C(s) → SiC(s) + 2CO(g)        ΔH° = 624.7 kJ/mol

First we convert 3.00 grams of SiO₂ to moles, using its molar mass:

• 3.00 g SiO₂ ÷ 60.08 g/mol = 0.05 mol

Now we calculate the heat absorbed, using the given ΔH°:

If the complete reaction of 1 mol of SiO₂ absorbs 624.7 kJ, then with 0.05 mol:

• 0.05 mol * 624.7 kJ/mol = 31.24 kJ of heat would be absorbed.