Question

According to the following thermochemical equation, what mass of H2O (in g) must form in order to produce 975 kJ of energy? SiO2(s) + 4 HF(g) → SiF4(g) + 2 H2O(l) ΔH°rxn = -184 kJ

Answer 1

Answer:

191g of water.

Explanation:

For the reaction:

SiO₂(s) + 4HF(g) → SiF₄(g) + 2H₂O(l) ΔH°rxn = -184 kJ

Two moles of water are formed and the reaction produce 184 kJ of energy. To produce 975 kJ of energy:

975 kJ energy ×$\frac{2molH_{2}O}{184 kJ}$ = 10,6 moles of H₂O

Using molar mass of water (18,02 g/mol), mass of H₂O must form when 975 kJ of energy are produced is:

10,6 moles of H₂O×$\frac{18,02g}{1molH_{2}O}$ = 191 g of water

I hope it helps!