Given the equation Si (s) + 2Cl2 (g) → SiCl2 (g) ? SiCl2 (l) + 687 kJ, how much heat is produced when 106 g of Cl2 react?

No of moles of Cl2 = mass of Cl2 / molar mass of Cl2

= 106g / (35.4*2) g/mol

= 106g / 70.9 g/mol = 1.495 moles

the heat produced = no of moles of Cl2 * ΔHrxn/2mol Cl2

when we have ΔHrxn from the equation = + 687 KJ so,

by substitution:

= 1.495 mol * 687 KJ/2 mol Cl2

= 513.5 KJ