Question

The energy required for the hypothetical reaction 2A+B⇌2C+2D is 389 kJ as written. How much heat is absorbed when 155 g of A reacts given that A has a molar mass of 46.59 g/mol?

Answer 1

Mol of A = mass of A / molar mass of A

= 155 g / 46.59 g/mol

= 3.327 mol

From reaction,

When 2 mol of A reacts, heat absorbed = 389 KJ

So,

When 3.327 mol of A reacts, heat absorbed = 389* 3.327 / 2

= 647 KJ

Answer: 647 KJ