Explain the fire polishing of glass.

What will be the pressure of the gaseous mixture when $0.5 \, L$ of $H_{2}$ at $0.8 \, bar$ and $2.0 \, L$ of dioxygen at $0.7 \, bar$ are introduced in a $1 \, L$ vessel at $27^{\circ} C$ (in $, bar$)?

At $STP$,$0.48 \, g$ of $O_2$ gas diffuses through a porous membrane in $1200 \, s$. What volume (in $mL$) of $CO_2$ gas will diffuse under the same conditions and in the same time?

$A$ $4 : 1$ molar mixture of $He$ and $CH_4$ is kept in a vessel at $20 \ bar$ pressure. Due to a hole in the vessel,the gas mixture leaks out. What is the composition of the mixture effusing out initially?

Why is it necessary for chemists to understand the laws that govern the physical states of matter?

Which of the following is a superfluid?