Ionic Compounds
The name for the compound formed between potassium (K) and chlorine (Cl).
Potassium chloride
This property generally decreases as you move from left to right across a period.
Atomic radius
The law that states that at a constant temperature, the pressure of a fixed amount of gas is inversely proportional to its volume (P ∝ 1/V).
Boyle's Law
The minimum amount of energy required for colliding particles to react.
Activation energy (Ea)
What is (dynamic) equilibrium?
The state in a reversible reaction where the rate of the forward reaction is equal to the rate of the reverse reaction.
The chemical formula for magnesium nitrate.
Mg(NO3)2
What is 'the energy required to remove one mole of electrons from one mole of gaseous atoms'?
First ionisation energy
The volume occupied by 1 mole of an ideal gas at STP (to 3 significant figures).
22.7 dm3 (or 22.7 L)
A substance that increases the rate of a chemical reaction without being consumed, by providing an alternative reaction pathway.
Catalyst
This principle states that if a change is made to a system at equilibrium, the system will shift to partially oppose that change.
Le Châtelier's Principle
The name for the compound Fe2(SO4)3.
Iron (III) sulfate
This element has the highest electronegativity.
Flourine (F)
The conditions of temperature and pressure defined by the IB as "STP" (Standard Temperature and Pressure).
273.15 K (0°C) and 100 kPa
This quantity is a measure of the average kinetic energy of the particles in a substance.
Temperature
The correct equilibrium constant expression (Kc) for the reaction:
N2(g) + 3 H2(g) ⇌ 2 NH3(g)
Kc = [NH3]2 / ([N2][H2]3)
The chemical formula for ammonium phosphate.
(NH4)3PO4
Explain why a sodium ion (Na+) is smaller than a sodium atom (Na).
The ion has one fewer electron shell (and the same nuclear charge pulling on fewer electrons)
A gas in a 2.0 L container at 1.0 atm and 200 K is heated to 400 K. What is the new pressure (assuming constant volume)?
2.0 atm
(Based on the Gay-Lussac Law, P1/T1 = P2/T2; since temperature doubles, pressure also doubles).
According to collision theory, the two factors that determine whether a collision will result in a reaction.
1. Sufficient kinetic energy (energy ≥ Ea)
2. Correct collision geometry (orientation)
For the exothermic reaction N2(g) + 3 H2(g) ⇌ 2 NH3(g), this change in conditions will increase the yield of ammonia (NH3).
(Pick any 1, good if you know all).
Increasing the pressure OR decreasing the temperature.
The name for the compound Cu2O.
Copper (I) oxide
Explain the general trend for first ionization energy as you go down Group 1 (with a reason).
It decreases, because the valence electron is in a higher energy level (further from the nucleus) and experiences more shielding.
Calculate the pressure of 0.500 moles of an ideal gas in a 10.0 dm3 container at 298 K. (R = 8.31 J K-1 mol-1). Give the correct unit as well.
124 kPa
Calculation: P = nRT/V = (0.500 mol * 8.31 J K-1 mol-1 * 298 K) / 0.0100 m3 = 123867 Pa ≈ 124 kPa)
How a catalyst affects the activation energy (Ea) and the overall enthalpy change (ΔH) of a reaction?
It lowers the activation energy (Ea) but has no effect on the enthalpy change (ΔH)
For the reaction N2(g) + 3 H2(g) ⇌ 2 NH3(g), the Kc at 500 K is 0.145.
In a container, [N2] = 1.0 M, [H2] = 1.0 M, and [NH3] = 0.20 M. Calculate the reaction quotient (Qc) and predict the direction of the shift.
Qc = 0.040. Since Qc (0.040) < Kc (0.145), the reaction will shift to the right (towards the products)?
(Calculation: Qc = [NH3]2 / ([N2][H2]3) = (0.20)2 / (1.0 * (1.0)3) = 0.040 / 1.0 = 0.040)