Chemistry

An ideal gas at constant temperature and pressure expands and its

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(a) internal energy increases (b) internal energy decreases (c) internal energy remains same (d) endropy increases and then decreases

Correct Answer:

internal […]

Equal volumes of methanoic acid and sodium hydroxide are mixed, if x is the heat of formation of water, then heat evolved on neutralisation is

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(a) twice of x (b) equal to x […]

The neutralisation of a strong acid by a strong base liberates an amount of energy per mole of H⁺ that

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(a) depends upon which catalyst is used (b) depends upon the temperature at […]

If 900 J/g of heat is exchanged at boiling point of water, then what is increase in entropy

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(a) 900 J/mol (b) 87.2 J/mol (c) 43.4 J/mol (d) Zero

Correct Answer:

43.4 J/mol

[…]

The values of heat of formation of SO₂ and SO₃ are -298.2 kJ and -98.2 kJ. The heat of formation of this reaction will be SO₂ + (1/2)O₂ → SO₃

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(a) 200 kJ […]

The standard heat of formation of carbon disulphide (l) given that the standard heat of combustion of carbon(s) , sulphur(s) and carbon disulphide(l) are -393.3, -293.72 and -1108.76 kJ mol⁻¹ respectively is

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(a) […]

For the reaction C(s) + O₂(g)

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(a) ΔH = ΔE (b) ΔH < ΔE (c) ΔH > ΔE (d) either ΔH > ΔE or ΔH < ΔE

Correct Answer:

ΔH = ΔE

Explanation: […]

Heat of formation of H₂O(g) at 25⁰C is -243 kJ,ΔE for the reaction H₂(g) + 1/2 O₂(g) → H₂O(g) at 25⁰C is

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(a) -243 kJ (b) -241.8 kJ (c) 241.8 kJ (d) 243 […]

For an endothermic reaction the value of ΔS is positive.The reaction is

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(a) feasible when ΔH > TΔS (b) feasible when TΔS > ΔH (c) feasible at all temperatures (d) not feasible at […]