Q36 · CSIR-NET Chemistry, December 2014

Paper: CSIR-NET December 2014 · Subject: Physical Chemistry · Chapter: Thermodynamics · Topic: Laws State Functions · Marks: 2 · Difficulty: Easy

The exact differential $d f$ of a state function $f(x, y)$, among the following is

(a)$x d y$

(b)$d x-\frac{x}{y} d y$

(c)$y d x-x d y$

(d)$\frac{1}{y} d x-\frac{x}{y^{2}} d y$

Answer

Answer: D ✓ checked by 4AB · confidence high

The source book printed no answer; this one was worked out and checked — see the explanation.

Explanation

(1/y)dx − (x/y²)dy = d(x/y). The cross derivatives ∂(1/y)/∂y = −1/y² and ∂(−x/y²)/∂x = −1/y² are equal (d).

Study loop for Thermodynamics