Question

What are the units used in $PV{\text{ = nRT}}$.

Answer 1

Hint: In physical chemistry this relation is very important as this relation is valid for ideal gases and thus termed as ideal gas law. We can calculate pressure, volume of a gas in a closed container. The units which are used in this equation are independent of each other.

Complete answer:
The ideal gas equation for the ideal conditions is given by:
$PV{\text{ = nRT}}$
At a constant temperature the product of pressure and volume of the same number of moles of gas is always constant. Therefore at this condition pressure becomes inversely dependent on the volume. However, in the above gas equation there are different units which are pressure, volume, moles, temperature. Therefore these units are given below: $ml$
$P{\text{ = }}$ pressure of the gas inside the closed container at ideal conditions. The unit of pressure taken is Pascal.
${\text{V = }}$ Volume of the gas in the container under ideal conditions. The unit of volume is taken in litres. However if it is given in millilitres then we have to convert it into litres.
$n{\text{ = }}$ It is the number of moles of gas present inside the container at given volume and pressure. It has no unit as it is a ratio of mass to mass. Hence it is just a number , it has no unit.
${\text{R = }}$ Universal Gas constant. It is a constant quantity .Its value changes according to the units of pressure and volume. If the volume and pressure is taken in their standard units then its value is taken to be $8.314{\text{ J}}{{\text{K}}^{ - 1}}mo{l^{ - 1}}$ .
$T{\text{ = }}$ Temperature of the gas at ideal conditions. If temperature is not given then $298{\text{ K}}$ is the standard temperature which is to be taken. Its unit is Kelvin.

Note:
All the units are taken at STP which means standard temperature and pressure. Pressure can also be taken in $atm$ and volume can also be taken in $ml$ but the value of universal gas constant changes accordingly. Keep a note taking all units in the standard system.