When does $Z = 1$ occur?

The value of the gas constant $R$ depends on which of the following?

$22 \, g$ of dry ice is placed in a $600 \, mL$ empty container at $25 \, ^\circ C$ and sealed tightly. If all the $CO_2$ evaporates,what will be the final pressure inside the container in $atm$?

For an ideal gas,which of the following graphs will not be a straight line?

At $25^{\circ} C$ and $760 \,mm \,Hg$ pressure,a gas occupies $600 \,mL$ volume. What will be its pressure at a height where the temperature is $10^{\circ} C$ and the volume of the gas is $640 \,mL$?

In a $1 \ L$ flask,$N_2$ gas is at $100 \ kPa$ pressure,and in another $3 \ L$ flask,$O_2$ gas is at $320 \ kPa$ pressure. If both flasks are connected,what will be the resultant pressure in $kPa$?