D A(g) + B(g) C(g) endothermic (Total 1 mark) [Cu(H 2O) 6] H 2NCH 2CH 2NH 2 [Cu(H 2NCH 2CH 2NH 2) 2(H 2O) 2] H 2O (Total 1 mark)

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1 Q1.Which one of the equations below represents a reaction that is feasible at all temperatures? P(s) Q(s) + R(g) endothermic 2L(g) + M(g) 2N(g) exothermic S(g) 2T(g) exothermic (g) + (g) (g) endothermic Q2.Which one of the following reactions in aqueous solution has the most positive change in entropy? [u(h 2O) 6] NH 3 [u(nh 3) 4(H 2O) 2] H 2O [u(h 2O) 6] l [ul 4] 2 + 6H 2O [u(h 2O) 6] 2+ + ET 4 [u(et)] 2 + 6H 2O [u(h 2O) 6] H 2NH 2H 2NH 2 [u(h 2NH 2H 2NH 2) 2(H 2O) 2] H 2O Q3.Refer to the following reaction H 2(g) + I 2(g) 2HI(g) ΔH = 11 kj mol 1, ΔS = +20 J K 1 mol 1 Which one of the following statements is correct? This is a redox reaction. The reaction is not feasible below 298 K t equilibrium, the yield of hydrogen iodide is changed by increasing the pressure. t equilibrium, the yield of hydrogen iodide increases as the temperature is increased. PhysicsndMathsTutor.com Page 2

2 Q4.This question is about the reaction given below. O(g) + H 2O(g) O 2(g) + H 2(g) Enthalpy data for the reacting species are given in the table below. Substance O(g) H 2O(g) O 2(g) H 2(g) ΔH / kj mol Which one of the following statements is not correct? The value of K p changes when the temperature changes. The activation energy decreases when the temperature is increased. The entropy change is more positive when the water is liquid rather than gaseous. The enthalpy change is more positive when the water is liquid rather than gaseous. Q5.Which one of the following statements is not correct? The first ionisation energy of iron is greater than its second ionisation energy. The magnitude of the lattice enthalpy of magnesium oxide is greater than that of barium oxide. The oxidation state of iron in [Fe(N) 6] 3 is greater than the oxidation state of copper in [ul 2] The boiling point of 3H 8 is lower than that of H 3H 2OH PhysicsndMathsTutor.com Page 3

3 Q6.Using the information below, answer this question. Fe 2O 3(s) + 3H 2(g) 2Fe(s) + 3H 2O(g) ΔH = +96 kj mol 1, ΔS = +138 J K 1 mol 1 Fe 2O 3(s) H 2(g) Fe(s) ΔH / kj mol ΔS / J K 1 mol The standard entropy value for steam is +332 J K 1 mol J K 1 mol J K 1 mol J K 1 mol 1 Q7.In which one of the following reactions is there a decrease in entropy? [Fe(H 2O) 6] 3+ (aq) + 3 2O (aq) [Fe( 2O 4) 3] 3 (aq) + 6H 2O(l) [u(h 2O) 6] 2+ (aq) + ET 4 (aq) [u(et)] 2 (aq) + 6H 2O(l) [ol 4] 2 (aq) + 6H 2O(l) [o(h 2O) 6] 2+ (aq) + 4l (aq) Na 2O 3(s) + 2H + (aq) 2Na + (aq) + O 2(g) + H 2O(l) PhysicsndMathsTutor.com Page 4

4 Q8.This question relates to the equilibrium gas-phase synthesis of sulphur trioxide: 2SO 2(g) + O 2(g) 2SO 3(g) Thermodynamic data for the components of this equilibrium are: Substance ΔH / kj mol 1 S / J K -1 mol -1 SO 3(g) SO 2(g) O 2(g) This equilibrium, at a temperature of 585 K and a total pressure of 540 kpa, occurs in a vessel of volume 1.80 dm 3. t equilibrium, the vessel contains mol of SO 2(g), mol of O 2(g) and mol of SO 3(g). The standard entropy change for this reaction is 222 J K 1 mol J K 1 mol J K 1 mol J K 1 mol 1 Q9.Which one of the following best explains why the lattice enthalpy of magnesium chloride is much larger than that of lithium chloride? Magnesium has a greater electronegativity than lithium. Magnesium ions have a greater polarising power than lithium ions. Magnesium ions have a greater ionic radius than lithium ions. Magnesium ions have a greater charge than lithium ions. PhysicsndMathsTutor.com Page 5

5 Q10.Which one of the following has the most covalent character? MgF 2 Mgr 2 lf 3 lr 3 Q11.The following information concerns the equilibrium gas-phase synthesis of methanol. O(g) + 2H 2(g) H 3OH(g) t equilibrium, when the temperature is 68, the total pressure is 1.70 MPa. The number of moles of O, H 2 and H 3OH present are 0.160, and 0.180, respectively. Thermodynamic data are given below. Substance ΔH / kj mol 1 S / J K -1 mol -1 O(g) H 2(g) H 3OH(g) The standard entropy change for this reaction is 220 J K 1 mol J K 1 mol 1 89 J K 1 mol J K 1 mol 1 PhysicsndMathsTutor.com Page 6

6 Q12.The compound lithium tetrahydridoaluminate(iii), LilH 4, is a useful reducing agent. It behaves in a similar fashion to NaH 4. arbonyl compounds and carboxylic acids are reduced to alcohols. However, LilH 4 also reduces water in a violent reaction so that it must be used in an organic solvent. Which one of the following concerning the violent reaction between LilH 4 and water is false? gas is produced. The activation energy for the reaction is relatively high. The reaction has a negative free-energy change. queous lithium ions are formed. Q13.Which one of the following has the most covalent character? MgF 2 Mgr 2 lf 3 lr 3 PhysicsndMathsTutor.com Page 7