Cooking is fast in a pressure cooker,because

Which of the following statements is incorrect?

At $27^{\circ} C$,a closed vessel contains a mixture of equal weights of helium (mol. wt. = $4$),methane (mol. wt. = $16$) and sulphur dioxide (mol. wt. = $64$). The pressure exerted by the mixture is $210 \ mm$. If the partial pressures of helium,methane and sulphur dioxide are $p_1, p_2$ and $p_3$ respectively,which one of the following is correct?

Mechanical work is especially important in systems that contain

If $N_2, O_2, H_2$,and $He$ gases are filled separately in four car tubes at the same pressure,which gas will diffuse first?

What is the boiling point of $SO_2$ gas (in $K$)?