6 past paper MCQs on The Gas Constant R, from the Gases unit of MDCAT Chemistry. The year each question appeared is shown where known; tap “Show answer” for the correct option and a short solution.
1.If we want to raise the temperature of one mole of an ideal gas by one kelvin, how much energy do we have to provide? (MDCAT 2022)
Correct answer: (d) $0.0821\ \mathrm{dm^3\,atm}$
That energy is the gas constant itself, $R=8.314\ \mathrm{J\,mol^{-1}K^{-1}}=0.0821\ \mathrm{dm^3\,atm\,mol^{-1}K^{-1}}$.
2.Value of R gas constant in J mol-1 K-1 is (UHS MDCAT 2025)
Correct answer: (a) 8.314
In SI units the gas constant is $8.314\,\mathrm{J\,mol^{-1}\,K^{-1}}$.
3.The value of R in atm.dm3.mol-1.K-1 is: (KMU MDCAT 2025)
Correct answer: (a) 0.0821
In these units the gas constant is $0.0821\,\mathrm{atm\,dm^3\,mol^{-1}\,K^{-1}}$.
4.If we want to raise the temperature of one mole of an ideal gas by one kelvin, we have to provide how much amount of energy? (UHS MDCAT 2023)
Correct answer: (d) 0.0821 dm3·atm
That energy is the gas constant, $0.0821\,\mathrm{dm^3\,atm\,mol^{-1}\,K^{-1}}$.
5.The value of general gas constant ‘R’ for a particular gas is independant of: (PMC MDCAT 2022)
Correct answer: (d) Molar mass of the gas.
$R$ is the same for every gas, which is why it is called the universal gas constant.
6.Identify the value of R at STP: (UHS MDCAT 2017)
Correct answer: (c) 0.0821 atm dm3 K-1 mol-1
In these units the gas constant is $0.0821\,\mathrm{atm\,dm^3\,K^{-1}\,mol^{-1}}$.