The balloon has a volume of 500 cubic meters on Earth and a gas pressure in the envelope of 150 kPa

The balloon has a volume of 500 cubic meters on Earth and a gas pressure in the envelope of 150 kPa at a temperature of 300 K. What will the pressure in the balloon after ascent become, when the gas temperature is 200 KPa, and its volume increases from expansion to 800 cubic meters?

From the Mendeleev – Clapeyron equation (p1 ∙ V1) / Т1 = (p2 ∙ V2) / Т2 we express Т2 = (p2 ∙ V2 ∙ Т1) / (p1 ∙ V1). According to the condition of the problem, the balloon has a volume on the Earth V1 = 500 cubic meters. m and the gas pressure in the shell p1 = 150 kPa = 150,000 Pa at a temperature of T1 = 300 K, and after the rise p2 = 200 kPa = 200,000 Pa and its volume will increase from expansion to V2 = 800 cubic meters. m, which means, substituting the values of physical quantities into the formula, we get: T2 = (200,000 ∙ 800 ∙ 300) / (150,000 ∙ 500) = 640 (K).
Answer: 640 K will be the temperature in the balloon after the ascent.