Q. The plot of log₁₀ K vs 1/T gives a straight line. The intercept and slope respectively are (where K is equilibrium constant).

Correct Answer: ΔS° / 2.303R , − ΔH° / 2.303R

Solution

From thermodynamics, the van’t Hoff equation is:

ln K = − ΔH° / RT + ΔS° / R

Converting natural logarithm to base 10:

log₁₀ K = − ΔH° / (2.303RT) + ΔS° / (2.303R)

This equation is of the form:

y = mx + c

where:

y = log₁₀ K x = 1 / T

Comparing terms:

Slope = − ΔH° / 2.303R Intercept = ΔS° / 2.303R

Hence, the correct answer is:

ΔS° / 2.303R , − ΔH° / 2.303R

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