Given the balanced chemical equation, sio2(s) + 4 hf(g) → sif4(g) + 2 h2o(l) δh°rxn = −184 kj determine the mass (in grams) of hf(g) must react when 345 kj of energy is released.

mass HF = 150.05 g

Explanation:

⇒ Q = (ΔH°rxn * mHF) / (mol HF * MwHF )

∴ MwHF = 20.0063 g/mol

∴ mol HF = 4 mol

∴ ΔH°rxn = - 184 KJ

∴ Q = 345 KJ

mass HF ( mHF ):

⇒ mHF = ( Q * mol HF * MwHF ) / ΔH°rxn

⇒ mHF = ( 345 KJ * 4mol HF * 20.0063 g/mol ) / 184 KJ

⇒ mHF = 150.05 g HF

i think that the answer is c