A constant pressure calorimeter consists of an insulated beaker of mass `92g` made up of glass with heat capacity `0.75 J K^(-1) g^(-1)`. The beaker contains `100 mL` of `1M HCI` at `22.6^(@)C` to which `100 mL` of `1M NaOH` at `23.4^(@)C` is added. The final temperature after the complete reactions is `29.3^(@)C`, What is `DeltaH` per mole for this neutralization reaction? Assume that the heat capacities of all solutions are equal that of same volumes of water.

Answer

57 kj

Explanation

Initial average temperature of the the acid and base `= (22.6 + 23.4)/(2) = 23.0 .^(@)C`
Rise in temperature `= (29.3 - 23.0) = 63^(@)C`
Total heat produced `= (92 xx 0.75 + 200 xx 4.184) xx 6.3 = (905.8) xx 6.3 = 5706.54 J`
Enthaply of neutralisation `= - (5706.54)/(100) xx 1000 xx1 = - 57065.4 J = - 57 kJ`