Physical Chemistry Answers

Enthalpy change​ for the reaction 4H(g)→2H(g) is -869.6kJ. The dissociation energy of H-H bond is;
(1)-434.8kJ
(2)-869.6kJ
(3)434.8kJ
(4)217.4kJ

The standard enthalpies of formation of CO2(g) ,H2O(l) and glucose (s) at 25°C are-400kJ,-300 kJ/mol and-1300kJ/mol,respectively. The standard enthalpy of combustion per gram of glucose at 25°C is
(1)2900kJ
(2)-2900kJ
(3)-16.11 kJ
(4)16.11kJ

For a reaction A (g)→B(g) at equilibrium. The partial pressure of B is found to be one fourth of the partial pressure of A. The value of∆G°of the reaction A→B is
(1) RTln4
(2)-RTln4
(3) RTlog4
(4)-RTlog4

If 2 mole of H2 completely react with 2 mole of Cl2 to form HCl.What is ∆U° for this reaction?
(1)0
(2)-185kJ
(3)370kJ
(4)-370kJ

Inter mixing of ideal gas (at the same temperature) is example of and why?
(a) reversible isothermal
(b) irreversible isothermal and adiabatic
(c) reversible adiabatic
(d)none

25 ml of a solution containg NaOh and Na2CO3 required (I) 50 ml of 0.2 N HCl using phenolphthalein (2) 72 ml of 0.2 N HCl when tirated using methyl Orange as indicator. The ratio of weight of NaOH and Na2CO3 in the solution is
(1) 0.48. (2) 0.44
(3) 0.40. (4) 0.38

Explain important feature of standard hydrogen electrode giving the suitable diagram

Calculate the work done when 1.00 mil of an ideal gas expands isothermally and reversibly at 3.00*10^2 K from 2.00* 10^5 Pa

To a beaker that contains 100 mL of water and is thermally insulated from its surroundings, 1.0 mol of solid calcium chloride is added. The solution is stirred, and the temperature of the solution changes from room temperature to a temperature that is greater than 30 oC. The temperature change is caused by heat energy?

a) absorbed from the surroundings into the solution.
b) evolved from the surroundings to the solution.
c) evolved in dissolving and hydrating the solid CaCl2.
d) absorbed in dissolving and hydrating the solid CaCl2.
e) of the hydrated ions being higher than the ions in the solid CaCl