Question

Calculate the amount of heat released when heat of neutralization is -57.0 kJ :

(a) 0.5 mole of HNO3 is mixed with 0.3 mole of NaOH in aqueous solution.

(b) 200 mL of 0.1 MH2SO4 is mixed with 150 mL of 0.2 MKOH.

Answer 1

(a) 1 mole of HNO3 and 1 mole of NaOH give heat = 57.0 kJ

0.3 mole of HNO3 and 0.3 mole of NaOH give heat = 57 x 0.3 = 17.1 kJ

(b) Meq. of H2SO4 = 200 x 0.1 x 2 = 40;

Meq. of KOH = 150 x 0.2 x 1 = 30

1000 Meq. of H2S04 and 1000 Meq. of KOH on mixing produce heat = 57.0 kJ

30 Meq. of H2SO4 and 30 Meq. of KOH on mixing produce heat = 57x30 =1000 =1.71 kJ