Which amongst the following options is correct graphical representation of Boyle's law?

Four gas cylinders containing He, N_{2}, CO_{2} and NH_{3} gases separately are gradually cooled from a temperature of 500 K. Which gas will liquify first?

(Given Tc in K $$-$$ He : 5.3, N_{2} : 126, CO_{2} : 304.1 and NH_{3} : 405.5)

Which one is not correct mathematical equation for Dalton's Law of partial pressure? Here p = total pressure of gaseous mixture

where p_{i} = partial pressure of i^{th} gas

$${\chi _i}$$ = mole fraction of i^{th} gas in gaseous mixture where $${\chi _i}$$ = mole fraction of i^{th} gas in gaseous mixture

$$p_i^o$$ = pressure of i^{th} gas in pure state

A 10.0 L flask contains 64 g of oxygen at 27$$^\circ$$C. (Assume O_{2} gas is behaving ideally). The pressure inside the flask in bar is (Given R = 0.0831 L bar K^{$$-$$1} mol^{$$-$$1})