1. Predict and explain the variation in enthalpy change of hydration for the ions F⁻, Cl⁻, Br⁻ and I⁻.
A. The enthalpy change of hydration becomes less negative as the ionic radius increases.
B. The enthalpy change of hydration becomes more negative as the ionic radius increases.
C. The enthalpy change of hydration is constant because all are halide ions.
D. The enthalpy change of hydration depends only on the charge of the ion.
2. Complete the energy cycle line D (states included):
A. Ca²⁺(aq) + 2F⁻(aq)
B. CaF₂(aq)
C. Ca²⁺(s) + 2F⁻(s)
D. CaF₂(g)
3. Identify the 5 required enthalpy terms for Process 1:
A. Ca atomisation
B. 1st Ca ionisation
C. 2nd Ca ionization
D. F₂ bond energy
E. F electron affinity
F. CaF₂ lattice energy
4. Define lattice energy (ΔHₗₐₜₜ):
A. Energy needed to break 1 mole of solid into gaseous ions
B. Energy released when 1 mole of solid forms from gaseous ions
C. Energy released when 1 mole of solid forms from its element
D. Energy released during hydration
6. Give the mathematical relationship between ΔHₗₐₜₜ of CaF2 and the enthalpy changes for processes 1 and 3.
A. ΔHₗₐₜₜ = ΔH(process1) + ΔH(process3)
B. ΔHₗₐₜₜ = ΔH(process1) - ΔH(process3)
C. ΔHₗₐₜₜ = -ΔH(process1) - ΔH(process3)
D. ΔHₗₐₜₜ = ΔH(process3) - ΔH(process1)
Calculate the enthalpy change of hydration of chloride ions in magnesium chloride using the following data:
A) −364 kJ/mol
B) −384 kJ/mol
C) −404 kJ/mol
D) −761 kJ/mol
Which equation correctly represents the lattice energy of silver bromide (AgBr)?
A) Ag(g) + Br(g) → AgBr(s)
B) Ag⁺(g) + Br⁻(g) → AgBr(s)
C) Ag(s) + ½Br₂(g) → AgBr(s)
D) Ag⁺(aq) + Br⁻(aq) → AgBr(s)
Using the following thermodynamic data, calculate the lattice energy of AgBr(s):
A) −815 kJ mol⁻¹
B) −865 kJ mol⁻¹
C) −903 kJ mol⁻¹
D) −945 kJ mol⁻¹
How does the lattice energy of silver chloride (AgCl) compare to that of silver bromide (AgBr), and what is the primary reason for this difference?
A) AgCl has a more negative energy value because Cl⁻ is larger than Br⁻
B) AgCl has a more negative energy value because Cl⁻ is smaller than Br⁻
C) AgCl has the same lattice energy as AgBr because both contain Ag⁺
D) AgCl has a more positive energy value because Cl⁻ is more electronegative than Br⁻
In photographic emulsions, the process of electron release from halide ions (X⁻ → X + e⁻). Compare the energy required for this process in AgCl versus AgBr:
A) AgCl requires less energy because Cl⁻ has higher electronegativity than Br⁻
B) AgCl requires more energy because Cl⁻ holds its electrons more tightly than Br⁻
C) AgBr requires more energy because Br⁻ has a larger atomic radius than Cl⁻
D) Both require the same energy because they contain the same silver cation (Ag⁺)
Which metal hydrocarbonate decomposes at a lower temperature?
A) Sodium hydrocarbonate
B) Potassium hydrocarbonate
C) Calcium hydrocarbonate
D) Magnesium hydrocarbonate
Which metal nitrate requires the highest temperature to decompose?
A) Lithium nitrate
B) Potassium nitrate
C) Barium nitrate
D) Lead(II) nitrate
why is BaSO₄ much less soluble in water than MgSO₄?
A) Both hydration and lattice energies become less exothermic for BaSO₄, but hydration energy dominates
B) Both processes become less exothermic for BaSO₄, but lattice energy dominates
C) The larger size of Ba²⁺ makes it interact more weakly with water molecules compared to Mg²⁺
D) Ba²⁺ forms stronger ion-dipole interactions with water than Mg²⁺
Which calculation correctly determines the standard enthalpy of formation of OH⁻(g), ?
A) -925 = 148 + 736 - 2993 +
B) -925 = 148 + (736 + 1450) + 2 - 2993
C) -925 = 148 + 1450 - 2993 +
D) -925 = 736 + 1450 +2 - 2993
Determine the Second Electron Affinity (EA₂) of Oxygen Using Born-Haber Cycle. Given the following thermochemical data for magnesium oxide (MgO):
A) -602 = 148 + (736 + 1450) + 498 + (-141) + EA₂ - 3791
B) -602 = 148 + (736 + 1450) + ½(498) + (-141) + EA₂ - 3791
B) -602 = 148 + (736 + 1450) + ½(498) + (-141) + EA₂ - 3791
D) -602 = (736 + 1450) + ½(498) + EA₂ - 3791