Title 9701_s25_qp_12.pdf ✅

2 © UCLES 2025 9701/12/M/J/25 1 Consider the following statements. 1 Silicon dioxide has a higher melting point than sulfur dioxide. 2 Ammonia has a higher boiling point than phosphine, PH3. Which statements are correct? A both statement 1 and statement 2 B statement 1 only C statement 2 only D neither statement 1 nor statement 2 2 How many neutrons are contained in an atom of iron with a mass number of 60? A 26 B 30 C 34 D 60 3 The diagram shows a Boltzmann distribution of molecular energies for a gaseous reaction at two different temperatures and two different activation energies. proportion of molecules energy / kJ mol–1 EA(1) EA(2) T1 T2 Which combination of temperature and activation energy will give the highest reaction rate? A T1 and EA(1) B T1 and EA(2) C T2 and EA(2) D T2 and EA(1)

4 © UCLES 2025 9701/12/M/J/25 8 In the Haber process, the reaction between the two gaseous reactants requires the use of a catalyst that contains a transition element. What is the metal and in which mole ratio do the gases react? metal mole ratio A Fe 1 : 2 B Fe 1 : 3 C V 1 : 2 D V 1 : 3 9 Aqueous hydrogen peroxide, H2O2, decomposes into water and oxygen in the presence of a suitable catalyst. 50 cm3 of a 0.50 moldm–3 solution of hydrogen peroxide produced 120 cm3 of oxygen in 2.0 minutes. The volume of gas was measured at room conditions. What is the average rate of decomposition of hydrogen peroxide during this 2.0 minute period? A 0.000083 mol dm–3 s–1 B 0.00083 moldm–3 s–1 C 0.0017 mol dm–3 s–1 D 0.10 mol dm–3 s–1 10 The average intermolecular forces in water are much stronger than the average intermolecular forces in steam. The average intermolecular forces in ice are slightly stronger than the average intermolecular forces in water. Enthalpy changes are associated with the equilibrium processes shown. H2O(l) H2O(g) Hb H2O(s) H2O(l) Hm Which statements are correct? 1 Hb and Hm are both negative. 2 Hb is greater than Hm. 3 The intermolecular forces in ice and water are of the same type. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only