phy chem ..dbts

Q1 If ΔHionisation (HCN)=45.2 kJ/mol and ΔHionisation (CH3COOH)=2.1 kJ/mol.Then whats relation ship between pKa of both ??

I am getting pKa(HCN)=45.2/2.1 pKa(CH3COOH)

Q2 Find change in deg of disociation be addn of 8.2 gm of CH3COONa in 1L 0.1M CH3COO

Q3 The entalpy of neutralization of HCl by NaOH is -55.9Kj/mol. whereas of HCN by NaOH is -12.1 Kj/molThe enthalpy of ionisaton of HCN is ??

3 Answers

106
Asish Mahapatra ·

Q3. 55.9-12.1

if it was strong acid then -55.9 kJ energy wud have evolved

But some energy is spent to ionise it

24
eureka123 ·

ya thats fine ..but sign is posiitve or negative ????

106
Asish Mahapatra ·

postive (ionisation is endothermic)

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