1. a. Under high pressure and/or low temperature conditions, molecules are much closer together and so do not behave like "ideal gases."
b. Real gases are most commonly observed in nature because the temperature and pressure conditions in nature are not usually extreme.
2.
- Ideal Gases (Kinetic Molecular Theory):
- Molecules are far apart.
- There is no attraction (intermolecular forces) between molecules.
- Collisions between molecules are elastic.
- Molecules move continuously in rapid, random motion.
- Real Gases:
- Molecules may be close together.
- Molecules are attracted to each other (strong intermolecular attraction).
- Collisions are inelastic and molecules lose energy when they collide.
- Molecules have no motion (absolute zero) or move very slowly.
3.
a. 2 mole of O₂ gas @ STP: # of Molecules = 1.204 × 10²⁴, Mass = 64.00 g, Volume = 44.8 L
b. 2 moles of CO₂ gas @ STP: # of Molecules = 1.204 × 10²⁴, Mass = 88.02 g, Volume = 44.8 L
c. 1 mole of O₂ gas @ STP: # of Molecules = 6.02 × 10²³, Mass = 32.00 g, Volume = 22.4 L
d. 1 moles of CO₂ gas @ STP: # of Molecules = 6.02 × 10²³, Mass = 44.01 g, Volume = 22.4 L
e. 0.5 mole of O₂ gas @ STP: # of Molecules = 3.01 × 10²³, Mass = 16.00 g, Volume = 11.2 L
f. 0.5 mole of CO₂ gas @ STP: # of Molecules = 3.01 × 10²³, Mass = 22.01 g, Volume = 11.2 L
4. The mass of the molecules does not affect the volume of the gas. The sizes of the molecules are very small compared to the amount of space between them, so they do not contribute significantly to the overall volume of the gas.
5. 11.2 L
II.
P = 1 atm
n = ? (to be solved)
V = 5.60 L
R = 0.0821 L·atm/(mol·K)
T = 273 K
PV = nRT → n = PV / RT
n = (1 atm × 5.60 L) / (0.0821 L·atm/(mol·K) × 273 K)
n ≈ 0.250 mol
Parent Tip: Review the logic above to help your child master the concept of ideal gas law practice worksheet.
