The rate of diffusion of $H_2$ is .......

Assertion : Wet air is heavier than dry air.
Reason : The density of dry air is more than density of water.

Fill in the blanks:
$(1)$ Each line of the graph of pressure versus temperature (in Kelvin) at a specific molar volume is called ........... .
$(2)$ $A$ gas that strictly follows Boyle's,Charles's,and Avogadro's laws is called ........... .
$(3)$ The ratio of the most probable speed to the average speed is ........... .
$(4)$ The ratio of $U_{rms}$ to $U_{mp}$ is ........... .

Assertion : Ice melts faster at high altitude.
Reason : At high altitude,atmospheric pressure is high.

The graph shows the characteristics of one mole of an ideal gas at a pressure of $1 \ atm$ with respect to volume $(V)$ and temperature $(T)$. Identify the correct graph.

What is the ratio of kinetic energies of $3 \ g$ of hydrogen and $4 \ g$ of oxygen at a certain temperature?