VJC H2 Chem 2013 Prelim P1 QP & Soln

2  VJC 2013 9647/01/13 Section A For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 25.0 cm 3 of a solution of hydrogen peroxide, H 2O2, was oxidised by excess potassium manganate(VII) solution under acidic condition. The volume of oxygen gas produced at room temperature and pressure was 26 cm3. What is the concentration of hydrogen peroxide in the solution? A 2.89 x 10 –2 mol dm–3 C 8.66 x 10–2 mol dm–3 B 4.33 x 10–2 mol dm–3 D 1.30 x 10–1 mol dm–3 2 The equations for three reactions are given below. Cl 2 + 2I–  2Cl– + I2 2Fe3+ + 2I–  2Fe2+ + I2 Cl2 + 2Fe2+  2Cl– + 2Fe3+ What is the correct order of strength of Cl –, Fe2+ and I– as reducing agents? weakest  strongest A Cl– I– Fe 2+ B Cl– Fe2+ I– C Fe2+ I– Cl– D I– Cl– Fe 2+ 3 In which one of the following pairs does the first species have a higher first ionisation energy than the second one? A Sb, Te B Kr, Ar C Mg +, Al+ D Se, Se+ 4 The use of the Data Booklet is relevant to this question. Consider the following chlorine–containing species: ICl 2 , ClF3, ClO3  Which one of the following statements is incorrect? A Not all atoms achieve stable octet configuration. B ICl2  is linear, ClF3 is T–shaped while ClO3  is trigonal pyramidal. C The bond angles increase in the order of ClF3, ClO3  , ICl2 . D The oxidising power decreases in the order of O2, F2, Cl2, I2. 1473

3  VJC 2013 9647/01/13 [Turn Over 5 Refer to the molecule below: Which one of the following shows the correct information with regard to the various labeled bond angles? smallest bond angle  largest bond angle A c d e B d a c C e b a D b e d 6 A graph of  / p versus p is obtained for a real gas Z at 273 K. [ = density of gas in g dm3, p = pressure of gas in Pa] What is the relative molecular mass of Z at 273 K? A 273RY B R 273Y C YR 273 D Y R 273 7 Which one of the following equations represents a reaction that is feasible at all temperatures? A W(s)  X(s) + Y(g) H > 0 B 2T(g) + 3U(g)  4V(g) H < 0 C R(g)  2Q(g) H < 0 D K(g) + L(g) → M(g) H > 0 p  / p 0 Y a b c e d 1474

4  VJC 2013 9647/01/13 8 The rate of the reaction 3D(g) + E(g)  G(g) is given by the rate equation, rate = k [D]2[E]. Two experiments using the same initial amounts of D and E were carried out at temperature, T. The data is shown below. experiment volume of reaction vessel initial rate of reaction 1 V R 1 2 2V R2 Which one of the following shows the correct relationship between R 1 an