States of Matter and Gas Laws Practice Questions & Answers

According to the Kinetic Molecular Theory, gas particles are separated by large distances relative to their size, making them easily compressible. Solids and liquids have particles packed closely together, making them virtually incompressible.

One of the fundamental postulates of the Kinetic Molecular Theory is that the average kinetic energy of gas particles is directly proportional to the absolute temperature (in Kelvin) of the gas.

Liquids have strong enough intermolecular forces to maintain a definite volume, but the particles have enough energy to slide past one another, allowing the liquid to flow and take the shape of its container.

Using Boyle's Law ($P_1V_1 = P_2V_2$P1​V1​=P2​V2​): $(2.0\ \text{atm})(4.0\ \text{L}) = P_2(1.0\ \text{L})$(2.0 atm)(4.0 L)=P2​(1.0 L) ​$8.0 = P_2$8.0=P2​ ​$P_2 = 8.0\ \text{atm}$P2​=8.0 atm.

Charles's Law states that Volume is directly proportional to Temperature in Kelvin ($V \propto T$V∝T). Graphically, this is a straight line passing through the origin.

First, convert temperatures to Kelvin: $T_1 = 25 + 273.15 = 298.15\ \text{K}$T1​=25+273.15=298.15 K ​$T_2 = -10 + 273.15 = 263.15\ \text{K}$T2​=−10+273.15=263.15 K Using Charles's Law ($\frac{V_1}{T_1} = \frac{V_2}{T_2}$T1​V1​​=T2​V2​​): $V_2 = V_1 \times \frac{T_2}{T_1} = 2.50 \times \frac{263.15}{298.15} \approx 2.21\ \text{L}$V2​=V1​×T1​T2​​=2.50×298.15263.15​≈2.21 L.

As temperature increases, the average kinetic energy of the particles increases. This causes them to move faster, striking the container walls more often and with more force, resulting in higher pressure.

Use Gay-Lussac's Law ($\frac{P_1}{T_1} = \frac{P_2}{T_2}$T1​P1​​=T2​P2​​). Convert to Kelvin: $T_1 = 300\ \text{K}, T_2 = 400\ \text{K}$T1​=300 K,T2​=400 K ​$\frac{3.0}{300} = \frac{P_2}{400} \implies P_2 = 3.0 \times \frac{400}{300} = 4.0\ \text{atm}$3003.0​=400P2​​⟹P2​=3.0×300400​=4.0 atm.

Boyle's Law states that for a fixed amount of gas at constant temperature, pressure and volume are inversely proportional, which is mathematically expressed as $PV = k$PV=k or $P_1V_1 = P_2V_2$P1​V1​=P2​V2​.

Avogadro's Law states that volume is directly proportional to the number of moles ($V \propto n$V∝n). Therefore, doubling the moles doubles the volume.