2017年11月IB化学SL真题下载-Paper2
1. A student titrated an ethanoic acid solution, CH3COOH (aq), against 50.0 cm3 of 0.995 mol dm-3 sodium hydroxide, NaOH (aq), to determine its concentration. The temperature of the reaction mixture was measured after each acid addition and plotted against the volume of acid.
(a) Using the graph, estimate the initial temperature of the solution.
(b) Determine the maximum temperature reached in the experiment by analysing the graph.
(c) Calculate the concentration of ethanoic acid, CH3COOH, in mol dm-3.
(d) (i) Determine the heat change, q , in kJ, for the neutralization reaction between ethanoic acid and sodium hydroxide.Assume the specific heat capacities of the solutions and their densities are those of water.
(ii) Calculate the enthalpy change, ΔH, in kJ mol-1, for the reaction between ethanoic acid and sodium hydroxide.
(e) Curves X and Y were obtained when a metal carbonate reacted with the same volume of ethanoic acid under two different conditions.
(i) Explain the shape of curve X in terms of the collision theory.
(ii) Suggest one possible reason for the differences between curves X and Y.
2. Trends in physical and chemical properties are useful to chemists.
(a) Explain the general increasing trend in the first ionization energies of the period 3 elements, Na to Ar.
(b) Explain why the melting points of the group 1 metals (Li → Cs) decrease down the group.
(c) State an equation for the reaction of phosphorus(V) oxide, P4O10 (s), with water.
(d) Describe the emission spectrum of hydrogen.
(e) The Activity series lists the metal in order of reactivity.
(i) Identify the strongest reducing agent in the given list.
(ii) A voltaic cell is made up of a Mn2+/Mn half-cell and a Ni2+/Ni half-cell.Deduce the equation for the cell reaction.
(iii) The voltaic cell stated in part (ii) is partially shown below.Draw and label the connections needed to show the direction of electron movement and ion flow between the two half-cells.
2017年11月IB化学SL真题余下省略！
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