Thermodynamics's Question 62 | Chemistry XI - Part 1 | NCERT Exemplar Questions

Physical Chemistry

Some Basic Concepts of Chemistry Structure of Atom States of Matter Thermodynamics Equilibrium

Inorganic Chemistry

Classification of Elements and Periodicity in Properties Chemical Bonding and Molecular Structure

NCERT

Physics XI - Part 1 Physics XI - Part 2 Chemistry XI - Part 1 Chemistry XI - Part 2 Mathematics XI Physics XII - Part 1 Physics XII - Part 2 Chemistry XII - Part 1 Chemistry XII - Part 2 Biology XI Mathematics XII - Part 1 Mathematics XII - Part 2

Subjective

Graphically show the total work done in an expansion when the state of an ideal gas is changed reversibly and isothermally from $\left(p_i, V_i\right)$ to $\left(p_f, V_f\right)$. With the help of a $p V$ plot compare the work done in the above case with that carried out against a constant pressure $p_f$.

Explanation

(i) Total work done in an expansion when the state of an ideal gas is changed reversibly and isothermally from $\left(p_i V_i\right)$ to $\left(p_f, V_f\right)$. Reversible work is represented by the combined areas $A B C$ and $B C V_i V_f$.

(ii) Work against constant pressure, $p_f$ is represented by the area $B C V_i V_t$. Work (i) $>$ work (ii)