The heat liberated when 1.89 g of benzoic acid is burnt in abomb calorimeterat25^(@)Cincreases the temperature of18.94kgof water by 0.632^(@)C. If the specific heat of water at25^(@)C is 0.998cal// g// deg, the value of heat of combustion of benzoic acid is

The heat liberated when 1.89 g of benzoic acid is burnt in abomb calor

1.	The heat liberated when 1.89 g of benzoic acid is burnt in abomb calorimeterat25^(@)Cincreases the temperature of18.94kgof water by 0.632^(@)C. If the specific heat of water at25^(@)C is 0.998cal// g// deg, the value of heat of combustion of benzoic acid is
Answer» `881.1kcal` `771.4 KCAL` `981.1kcal` `871.2kcal` Solution :Heat absorbed by water `= m xx s xx DELTAT` `= 18940 g xx 0.998 cal^(-1) g deg^(-1) xx 0.632 ^(@) C` `=11946.14 cal` `:. ` Heat produced on combustion of1.89g of benzoic ACID`= 11946.14cal` Molar mass of benzoic acid `( C_(6)H_(5) COOH) = 122g` `:. `Molar heat of combustion `= ( 11946.14)/( 1.89) xx 12 cal` `=771126.5 cal = 771.12 kcal`.