Question

120 cm ^3 of a gas is at a temperature of 20 deg C.If its temperature is raised to 40 deg C at constant pressure and moles.Calculate its new volume.

Answer 1

We use the ideal gas law. PV = nRT, where P is the pressure of the gas, V is the volumn, n is the amount in moles, R is the gas constant, and T is the temperature.

We can set-up the gas law to relate two states of a gas like so. \[{P_1 V_1 \over n_1 R T_1} = {P_2 V_2 \over n_2 R T_2}\]

Here, we are given that pressure and moles remain constant, we are interested in the relationship between volume and temperature. Since pressure and amount remain the same, they cancel out on each side of the equal sign. The gas constant is the same for both states, so that also cancels. We now have\[{V_1 \over T_1} ={ V_2 \over T_2}\] We can easily solve for V_2.