Assertion: The heat absorbed during the isothermal expansion of an ideal gas against vacuum is zero.
Reason: The volume occupied by the molecules of an ideal gas is zero.

Options

A. Statement-1 is true, statement 2 is true, statement 2 is a correct explanation for statement.1
B. statement-1 is true, statement 2 is true, statement 2 is not a correc explanation for statement 1
C. statement 1 is ture, statement 2 is false
D. statement-1 is false, statement-2 is true

Answer

B

Explanation

By first law of thermodynamics `d q = dE + dW`. Under isothermal condition for ideal gas is zero. Also `(dE)_(T) = 0` as for ideal gas there is no change in internal energy at constant T due to no force of attraction between the molecular.
`:. Dq = 0 + 0 = 0` hence, (B) is correct option