With an increase in the absolute temperature by 1.4 times, the gas volume increased by 40 cm3.

With an increase in the absolute temperature by 1.4 times, the gas volume increased by 40 cm3. Find the initial gas volume.

Under normal conditions in this problem, the pressure will be a constant value (p = const) and be 10 ^ 5 Pa. It follows from the Gay-Lussac law for the isobaric process:
V1 / T1 = V2 / T2.
From the conditions of the problem:
T2 = 1.4T1; V2 = V1 + 40 cm ^ 3.
It follows that V1 = (V2 * T1) / T2 = ((V1 + 40) * T1) / 1.4T1 = (V1 + 40) / 1.4;
1.4V1 = V1 + 40; 1.4V1-V1 = 40; 0.4V1 = 40; V1 = 100 cm ^ 3.
Answer: The initial gas volume was 100 cm ^ 3.