Question

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 1

Initial average temperature of the acid and base
`=(22.6+23.4)/(2)=23.0^(@)C`
Rise in temperature `=(29.3-23.0)=6.3^(@)C`
Total heat produced `=(92xx0.75+200xx4.184)xx6.3`
`=(905.8)xx6.3=5706.54J`
Enthalpy of neutralisation`=-(5706.54)/(100)xx1000xx1`
`=57065.4J=-57J`