Question

Two acid HX and HY have strength ratio of 5:2; their heat of neutralization are in ratio of 5:4. If 40 gm of NaOH indcate solution is added to a mixture of acids containing 1 equivalent each. The total heat involved is Q1. What is the ratio of Q1 and Q2, where Q2 is the heat of neutralization of HY

Answer 1

Answer:

1.Two acids are given in their strength ratio as 5:2. That means their ratios are 1:0.4

2.The acid is neutralsied by 1NNaOH.

[Normality ofNaOH= No of g equivalent vol of the solution inL=40/401=1N]

3.So the first one will indicate strong acid and strong base neutralisation whose enthalpy value is =−57.7kJ/mole

4.The second will indicate the weak acid strong base, so its neutralisation value is −55.8kJ/mole

5.The enthalpies are in the ratio of 5:4=5×−57.7:4×−55.8

6.Since the acids are in the strength ratio of 5:2=1:0.4ratio,

the enthalpy ratio =1×5×−57.7:0.4×4×−55.8=−288.5:−89.28=3.23:1

7.So their heat energies are in the ratio of 3.23:1.