When does $Z = 1$ occur?

For a fixed mass of an ideal gas,the following graph is given. Determine the correct relationship between $P_1, P_2$ and $P_3$.

Which of the following gases of the same mass exerts the highest pressure at a constant temperature?

$A$ gas occupies $2.5 \ L$ at $0 \ ^oC$ and $1 \ atm$ pressure. If the pressure is increased to $1.5 \ atm$ and the gas is transferred to a $2.0 \ L$ container,what will be the change in temperature in $^oC$?

The volume and pressure of a balloon filled with hydrogen gas are $1 \ bar$ and $175 \ dm^{3}$. When the balloon reaches a certain height,its pressure decreases to $0.8 \ bar$. Calculate the new volume of the balloon. (in $dm^{3}$)

Calculate the final volume of a gas when the pressure of $60 \ mL$ of gas is increased from $1 \ atm$ to $1.5 \ atm$,keeping the temperature constant.