Find the gas,if its density at $273 \ K$ temperature and $76 \ cm \ Hg$ pressure is $1.94 \ g / dm^3$.

An open vessel at $27\,^{\circ}C$ is heated until two-fifths of the air (assumed as an ideal gas) in it has escaped from the vessel. Assuming that the volume of the vessel remains constant,the temperature to which the vessel has been heated is:

$A$ certain sample of gas has a volume of $0.2 \ L$ at one atmosphere pressure and $273.15 \ K$. What is the volume of gas at $273.15 \ ^{\circ}C$ at the same pressure (in $L$)?

Keeping temperature constant,the pressure of $11.2 \ dm^3$ of a gas was increased from $105 \ kPa$ to $420 \ kPa$. What is the new volume of the gas (in $dm^3$)?

At $300 \ K$ temperature,the pressure and volume of a gas are $1 \ bar$ and $10 \ L$ respectively. If the pressure becomes $2 \ bar$,calculate the volume of the gas at the same temperature. (in $L$)

In an experiment during the analysis of a carbon compound,$145 \ L$ of $H_2$ was collected at $760 \ mm \ Hg$ pressure and $27 \ ^oC$ temperature. The mass of $H_2$ is nearly $....... \ g$.