Physics 2021 JAMB Past Questions - Question 16: A closed jar contains air at 1 atmosphere and 27°C. when the jar is heated to 127°C, what will be the pressure increase?

Correct Answer

C

Explanation

To calculate the pressure increase, you can use the ideal gas law, which states that PV = nRT, where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature in Kelvin.

First, you need to convert the temperatures to Kelvin by adding 273.15 to each temperature. So, 27°C = 27 + 273.15 = 300.15 K, and 127â�°C = 127 + 273.15 = 400.15 K.

Now, assuming the volume and the number of moles of gas remain constant, you can use the formula (P2 - P1) = nR(T2 - T1)/V to find the pressure increase.

Let's assume the initial pressure is P1 = 1 atm and the final pressure is P2. Also, let's assume the volume V, the number of moles n, and the gas constant R remain constant.

So, the pressure increase (ΔP) can be calculated as follows:
ΔP = P2 - P1 = nR(T2 - T1)/V
ΔP = (1 atm)(400.15 K - 300.15 K)/V

Assuming V, n, and R are constant, you can calculate the pressure increase using the given temperatures and initial pressure.