Answer to Question #241933 in Chemistry for Help me please

Question

If the reaction below produces 5,595.0 kJ of energy, how many grams of KCl will be produced? (KCl = 74.6 g/mol)

 

2 K (s) + Cl₂ (g) à 2 KCl (g)      ΔH_rxn =  –873.0 kJ  

Answer 1

Solution:

The balanced thermochemical equation:

2K(s) + Cl₂(g) → 2KCl(g), ΔH_rxn = –873.0 kJ

The equivalences for this thermochemical equation are:

2 mol K ⇔ 1 mol Cl₂ ⇔ 2 mol KCl ⇔ 873.0 kJ

Use the thermochemical equation to determine the moles of KCl:

5595.0 kJ × (2 mol KCl / 873.0 kJ) = 12.818 mol KCl

The molar mass of KCl is 74.6 g/mol

Hence,

(12.818 mol KCl) × (74.6 g KCl / 1 mol KCl) = 956.213 g KCl = 956.2 g KCl

Answer: 956.2 grams of KCl will be produced.