The amount of heat evolved when `500 cm^(3) 0.1 M HCl` is mixed with `200 cm^(3)` of `0.2 M NaOH` is

Options

A. 2.292 kJ
B. 1.292 kJ
C. 0.292 kJ
D. 3.392 kJ

Answer

A

Explanation

Mili-equivalent of HCl `=500 xx 0.1` = 50 milli-moles = 0.05 moles
Milli- equivalent of NaOH `=200 xx 0. 40` milli -moles = 0.04 moles
When 1 mole of `H^(+)` ions and 1 mole of `OH^(-)` ions are neutralized, 1 mole of water is formed adn 57.1 kJ of energy is released. 0.04 moles of `H^(+)` ions react with 0.04 moles of `OH^(-)` ions to form 0.04 moles of water molecules. Heat evolved `=0.04 xx 57.1 = 2.29` kJ