Please help me with this heat problem in chemistry

Question

Calculate the ΔH°_rxn for the following reaction.

SiO₂(s) + 4 HCl(g)  SiCl₄(g) + 2 H₂O(g)

You have the following data.

ΔH°_f [SiO₂(s)] = -910.9 kJ/mol

ΔH°_f [SiCl₄(g)] = -657.0 kJ/mol

ΔH°_f [HCl(g)] = -92.3 kJ/mol

ΔH°_f [H₂O (g)] = -241.8 kJ/mol

A. -139.5 kJ

B. 139.5 kJ     

C. 104.4 kJ

D. 104.4 kJ

E.-137.4 kJ

Answer 1

SiO₂(s) + 4 HCl(g)  SiCl₄(g) + 2 H₂O(g) ... balanced equation

The ∆Hrxn will be the sum fo the products - the sum of the reactants, or ∑n∆Hprod - ∑n∆Hreact)

Sum of products = (-657 + 2x-241.8) = -657 + -483.6 = -1140.6 kJ

Sum of reactants = -910.9 + 4x-92.3 = -910.9 + -369.2 = -1280.1 kJ

∆Hrxn = Products - Reactants = -1140.6 - (-1280.1) = 139.5 kJ (Answer B)