Which of the following has higher surface tension: pure water or soapy water?

In a closed flask of $5 \ L$,$1.0 \ g$ of $H_2$ is heated from $300 \ K$ to $600 \ K$. Which statement is not correct?

An empty $LPG$ cylinder weighs $14.8 \ kg$. When full,it weighs $29.0 \ kg$ and shows a pressure of $3.47 \ atm$. In the course of use at ambient temperature,the mass of the cylinder is reduced to $23.0 \ kg$. The final pressure inside of the cylinder is $....... \ atm$. (Nearest integer)
(Assume $LPG$ to be an ideal gas)

When $0.0168 \, mol$ of $O_2$ obtained from the decomposition of $KClO_3$ is collected over water at $25 \, ^\circ C$,the volume is $428 \, mL$ and the pressure is $754 \, mm$. What is the water vapor pressure at $25 \, ^\circ C$ in $mm$?

Which of the following mixtures of gases at room temperature does not obey Dalton's law of partial pressure?

Fill in the blanks:
$(1)$ Gases like $CO_2$ and $CH_4$ show ............ deviation from ideal gas behavior.
$(2)$ The temperature at which a real gas obeys ideal gas laws over an appreciable range of pressure is called ............ .
$(3)$ The maximum temperature below which a gas can be liquefied is called ............ .
$(4)$ The unit of coefficient of viscosity in the $CGS$ system is ............ .