Question

The volume of a perfect gas at NTP is
A. 22.4 litres
B. 2.24 litres
C. 100 litres
D. None of these

Answer 1

Hint: Normal Temperature and Pressure (NTP) is a condition like a Standard Temperature and Pressure (STP). It uses temperature as \[\text{2}{{\text{0}}^{\circ }}C\] and pressure as 1 atm.

Complete step by step answer: NTP is an acronym of Normal Temperature and Pressure. To find the molar volume of a perfect gas, we can consider that unit conditions.
\[\text{Pressure =1atm}\]
\[\text{Temperature =293K}\] i.e. \[\text{2}{{\text{0}}^{\circ }}C\]
Consider the ideal gas equation,
\[PV=nRT\]
R can be written as
\[\text{0}\text{.08205 atm}\text{.litre/mol}\text{.K= 8}\text{.314 J/mol}\text{.K}\]
So that volume will be,
\[\text{V=}\dfrac{1\times 0.08205\times 293}{1}\]
\[V=24.04L\]
Hence the correct answer is none of these.

Additional information:
To make a unity for measurements, IUPAC declared some standard conditions. STP and NTP are also standards made by IUPAC.
We can calculate molar volume at Standard Temperature and Pressure.
For an ideal gas,
Pressure is considered as 1 bar. It is actually equal to 0.987 atm. Its approximately equal to 1 atm. The temperature should be 293 K.
Molar volume of ideal gas at STP will be,
\[V=\dfrac{273\times 0.08205}{1}\]
\[V=22.3996\approx 22.4L\]
Standard Ambient Temperature and Pressure (SATP) is also used in chemistry as a standard. It is actually a reference with temperature of \[\text{2}{{\text{5}}^{\text{o}}}\text{C}\] and pressure of 101.325 kPa. At these conditions, volume of 1 mol of a gas will be 24.4651 L.
International Standard Atmosphere (ISA) used as a standard for aircraft performance. It is constrained to 101.325 kPa, \[\text{1}{{\text{5}}^{\text{o}}}\text{C}\] and 0% humidity.

Note: There are several types of standard conditions available. Even you can find different constraints for each standard. But IUPAC will define the correct standard. So, you should beware of that. According to IUPAC, \[{{20}^{\text{o}}}\text{C}\] of temperature and 1 atm are the conditions of NTP.