Home
Class 12
CHEMISTRY
Given Delta(i)H^(Theta)(HCN) = 45.2 kJ m...

Given `Delta_(i)H^(Theta)(HCN) = 45.2 kJ mol^(-1)` and `Delta_(i)H^(Theta)(CH_(3)COOH) = 2.1 kJ mol^(-1)`. Which one of the following facts is true?

A

`pKa(HCN) =pKa(CH_(3)CO_(2)H)`

B

`pKa(HCN) gt pKa(CH_(3)CO_(2)H)`

C

`pKa(HCN) lt pKa(CH_(3)CO_(2)H)`

D

`pKa(HCN) = (45.17)/(2.07) pKa(CH_(3)CO_(2)H)`

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Similar Questions

Explore conceptually related problems

Given : Enthalpy of ioinization of two acids : triangleH^(@)(HCN)=45.2 KJ mol^(-) triangleH^(@)(CH_(3)COOH)=2.1 KJ mol^(-) which relationshop for the two acids is true ?

Find DeltaH of the process NaOH(s) rarr NaOH(g) Given: Delta_(diss)H^(Theta)of O_(2) = 151 kJ mol^(-1) Delta_(diss)H^(Theta) of H_(2) = 435 kJ mol^(-1) Delta_(diss)H^(Theta) of O-H = 465 kJ mol^(-1) Delta_(diss)H^(Theta) of Na -O = 255 kJ mol^(-1) Delta_(soln)H^(Theta)of NaOH = - 46 kJ mol^(-1) Delta_(f)H^(Theta) of NaOH(s) =- 427 kJ mol^(-1) Delta_("sub")H^(Theta) of Na(s) = 109 kJ mol^(-1)

Calculate the enthalpy of combustion of benzene (l) on the basis of the following data: a. Resonance energy of benzene (l) =- 152 kJ// mol b. Enthalpy of hydrogenation of cyclohexene (l) =- 119 kJ//mol c. Delta_(f)H^(Theta)C_(6)H_(12)(l) =- 156 kJ mol^(-1) d. Delta_(f)H^(Theta) of H_(2)O(l) =- 285.8 kJ mol^(-1) e. Delta_(f)H^(Theta)of CO_(2)(g) =- 393.5 kJ mol^(-1)

Calculate the resonance energy of toluene (use Kekule structure from the following data C_(7)H_(8)(l) +9O_(2)(g) rarr 7CO_(2)(g) +4H_(2)O(l)+ DeltaH, DeltaH^(Theta) =- 3910 kJ mol^(-1) C_(7)H_(8)(l) rarr C_(7)H_(8)(g), DeltaH^(Theta) = 38.1 kJ mol^(-1) Delta_(f)H^(Theta) (water) =- 285.8 kJ mol^(-1) Delta_(f)H^(Theta) [CO_(2)(g)] =- 393.5 kJ mol^(-1) Heat of atomisation of H_(2)(g) = 436.0 kJ mol^(-1) Heat of sublimation of C(g) = 715.0 kJ mol^(-1) Bond energies of C-H, C-C , and C=C are 413.0, 345.6 , and 610.0 kJ mol^(-1) .

Calculate the standard Gibbs free energy change from the free energies of formation data for the following reaction: C_(6)H_(6)(l) +(15)/(2)O_(2)(g) rarr 6CO_(2)(g) +3H_(2)O(g) Given that Delta_(f)G^(Theta) =[C_(6)H_(6)(l)] = 172.8 kJ mol^(-1) Delta_(f)G^(Theta)[CO_(2)(g)] =- 394.4 kJ mol^(-1) Delta_(f)G^(Theta) [H_(2)O(g)] =- 228.6 kJ mol^(-1)

The standard Gibbs energy change value (Delta_(r)G^(Theta)) at 1773K are given for the following reactions: 4Fe +3O_(2) rarr 2Fe_(2)O_(3), Delta_(r)G^(Theta) = - 1487 kJ mol^(-1) 4AI +3O_(2) rarr 2AI_(2)O_(3),Delta_(r)G^(Theta) =- 22500 kJ mol^(-1) 2CO +O_(2) rarr 2CO_(2),Delta_(r)G^(Theta) =- 515 kJ mol^(-1) Find out the possibility of reducing Fe_(2)O_(3) and AI_(2)O_(3) with CO at this temperature.

The following data is known for melting of KCI: DeltaS^(Theta) = 0.007 kJ K^(-1) mol^(-1), DeltaH^(Theta) = 7.25 kJ mol^(-1) Calculate the melting point of KCI .

Ethanol was oxidised to acetic acid in a catalyst chamber at 18^(@)C . Calculate the rate of removel of heat to maintain the reaction chamber at 18^(@)C with the feed rate of 30 kg h^(-1) ethanol along with excess oxygen to the system at 18^(@)C , given that a 42 mol% yield based on ethanol is obtained. Given that Delta_(f)H^(Theta)underset(H_(2)O)'(l) =- 68.0 kcal mol^(-1) Delta_(f)H^(Theta)underset(C_(2)H_(5)OH)'(l) =- 66 kcal mol^(-1) Delta_(f)H^(Theta)underset(CH_(3)COOH)'(l) =- 118 kcal mol^(-1)

On the basic of the following Delta_(r)G^(Theta) values at 1073K : S_(1)(s) +2O_(2)(g) rarr 2SO_(2)(g) Delta_(r)G^(Theta) =- 544 kJ mol^(-1) 2Zn(s) +O_(2)(g) rarr 2ZnO(s) Delta_(r)G^(Theta) =- 480 kJ mol^(-1) 2Zn(s) +S_(2)(s) rarr 2ZnS(s) Delta_(r)G^(Theta) =- 293 KJ mol^(-1) Show that roasting of zinc sulphide to zinc oxide is a spontaneous process.

On the basic of the following Delta_(r)G^(Theta) values at 1073K : S_(1)(s) +2O_(2)(g) rarr 2SO_(2)(g) Delta_(r)G^(Theta) =- 544 kJ mol^(-1) 2Zn(s) +O_(2)(g) rarr 2ZnO(s) Delta_(r)G^(Theta) =- 480 kJ mol^(-1) 2Zn(s) +S_(2)(s) rarr 2ZnS(s) Delta_(r)G^(Theta) =- 293 KJ mol^(-1) Show that roasting of zinc sulphide to zince oxide is a spontaneous process.