For which of the following changes, ΔH ≠ ΔU
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Solution
ΔH = ΔU + Δn(g)RT;
Δn(g) = 1 in (d);
Δn(g) = 0 in other cases
Gibbs free energy,for the reaction at equilibrium, is
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Solution
The Gibb’s free energy is zero at equilibrium because the rate of backward reaction is equal to the rate of forward reaction.
Hence, option (a) is correct.
Which process takes place on chemical bond formation :
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Solution
When a chemical bond is formed between the two free atoms in a gaseous state to form a molecular product in a gaseous state, some heat is always evolved which is known as bond energy.
Hence, there is increase in energy.
The following is an endothermic reaction :
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Solution
Heat energy is absorbed during endothermic reaction.
In all the given reactions, heat is absorbed during reaction.
∴ All of them are endothermic reactions.
For the reaction
\(N_{2 \left ( g \right )} + 3H_{2 \left ( g \right )} \rightleftharpoons 2NH_{3 \left ( g \right )}, \triangle H = ?\)-
Solution
Δng = 2 – 4 = – 2, ΔH = ΔE – 2RT.
Which of the following is correct order ?
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Solution
107 erg = 1 Joule, 1 cal= 4.183 J
Hence calorie is the largest amount of energy.
If ΔH is the change in enthalpy and ΔE is change in internal energy accompanying a gaseous reaction, then
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Solution
As ΔH = ΔE + ΔngRT
if np < nr; Δng = np – nr = –ve
Hence ΔH < ΔE
In the isochoric process, ΔH for a system is equal to
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Solution
ΔH = ΔE + PΔV
For isochoric process, ΔV = 0
∴ ΔH = ΔE
Calorie is equivalent to :
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Solution
1 calorie = 4.184 joule
For precipitation reaction of Ag+ ions with NaCl, which of the following statements is correct ?
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Solution
Ag+(aq) + NaCl(aq) → AgCl(s) + Na+(aq)
The Precipitation reaction is spontaneous and hence
ΔGP, T <; 0.