Density of carbon monoxide is maximum at

At what new pressure will $100 \ mL$ of a gas at a pressure of $720 \ mm$ occupy a volume of $84 \ mL$,keeping the temperature constant (in $mm$)?

At what temperature will the volume of a gas be halved if the initial temperature is $17^{\circ}C$ and the pressure remains constant (in $^{\circ}C$)?

$A$ balloon contains $2.27 \ L$ of air and has a pressure of $1.013 \times 10^5 \ Nm^{-2}$. The balloon rises to a certain height and expands to a volume of $4540 \ mL$. What is the final pressure of air in the balloon?

In a closed vessel,an ideal gas at $1 \, atm$ is heated from $27^{\circ} C$ to $327^{\circ} C$. The final pressure of the gas will approximately be $..... \, atm$

State the combined gas law and the ideal gas equation.