For which gases does the ratio of PV to RT equal a constant? ideal gases gases at very high pressure gases of very low temperature real gases

Answer: Ideal Gases

Explanation: Ideal gases are the gases which are known to obey certain kinds of gas laws and have no inter molecular forces of attraction.

Thus ideal gas equation can be written as

PV = nRT

where P = Pressure of the given gas, V = volume of the gas, n = number of moles, R = gas constant and T = temperature of the maintained gas.

On the other hand, Real gases are the one which are known to obey the ideal gas equation and its laws at high temperature and low pressure. They have sufficient amount of forces of attraction.

It's one for ideal gases. by the way, remember that it's molar volume not volume itself and, this ratio is shown by Z and is called Compressibility factor.