Which one of the following statements is not correct?

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 ........... .

The density of gas $A$ is twice that of $B$. The molecular mass of $A$ is half of $B$. The partial pressure ratio of $A$ and $B$ is

At $27^{\circ} C$, $500 \ mL$ of helium diffuses in $30 \ minutes$. What is the time (in hours) taken for $1000 \ mL$ of $SO_2$ to diffuse under the same experimental conditions?

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

Which of the following statements is incorrect?