A real gas behaves like an ideal gas at

Which one of the following gas smells like a rotten egg?

For an ideal gas, which one of the following statements does not hold true?

Which gas is more easily liquified among following?

Which of the following gasses is/are lighter than air? 1. Hydrogen chloride 2. Sulfur dioxide 3. Helium

Which of the following represent the suitable condition for the liquefaction of gases?