$A$ flask of $1 \ L$ capacity is heated from $25 \ ^oC$ to $35 \ ^oC$. What volume of air (in $mL$) will be expelled from the flask?

$A$ vessel contains $1.6 \ g$ of dioxygen at $STP$ ($273.15 \ K$,$1 \ atm$ pressure). The gas is now transferred to another vessel at constant temperature,where pressure becomes half of the original pressure. Calculate
$(A)$ volume of the new vessel.
$(B)$ number of molecules of dioxygen.

$n$ moles of an ideal gas at temperature $T$ (in kelvin) occupy $V \ L$ of volume, exerting a pressure of $P$ atmospheres. What is the concentration (in $mol / L$)?

What is the relationship between the mass and volume of a gas?

Match the following graphs with their correct names:

Assuming the molar mass of air is $28.84 \, g \, mol^{-1}$,calculate the payload (lifting capacity) of a balloon of volume $10^6 \, L$ filled with $He$ at $27 \, ^\circ C$ and $1 \, atm$ pressure.