Question

What is the pressure at absolute zero?

Answer 1

Hint: Absolute zero is the temperature at which the pressure of the gas equals to zero. The pressure of a perfect vacuum, a void or space which has no matter at all is known as absolute zero pressure. It is not possible factually as it is very hard to reach the situation of perfect vacuum and also maintain the same for time being.

Complete answer:
Let us understand and answer the given question;
Let us consider, one mole of gas in one litre of volume is present whose temperature is 0 K. Using ideal gas law, we can solve for pressure at that point.
Given that,
P = x atm
V = 1 L
n = 1 mole
R = 0.0821 atmL/molK
T = 0 K
Thus, by ideal gas law,
\[\begin{align}
  & PV=nRT \\
 & P=\frac{nRT}{V}=\frac{1mol\times 0.0821atmL/molK\times 0K}{1L} \\
 & P=0atm \\
\end{align}\]

Note:
Do note that from the definition (actually, the name as well), we get a clear idea that the pressure will result as zero. But as it is asked to calculate or justify the same so without getting confused, we must solve what we know using the basics of gas laws.