9701_w17_qp_22
A paper of Chemistry, 9701
Questions:
4
Year:
2017
Paper:
2
Variant:
2
Login to start this paper & get access to powerful tools
1
The elements sodium to sulfur react with chlorine. The melting points of some of the chlorides formed are shown. chloride NaCl MgCl 2 Al Cl 3 SiCl 4 PCl 3 SCl 2 melting point / K Predict the shapes of Al Cl 3 and PCl 3. Draw diagrams to show the shapes, name the shapes and state the bond angles. Al Cl 3 shape angle PCl 3 shape angle Explain, in terms of structure and bonding, why the melting point of SiCl 4 is much lower than that of NaCl. Explain why the melting point of SiCl 4 is higher than that of PCl 3. Draw the ‘dot-and-cross’ diagram of a molecule of SiCl 4. Show outer electrons only. 
9. The Periodic Table: chemical periodicity  →  9.2. Periodicity of chemical properties of the elements in Period 3
9. The Periodic Table: chemical periodicity  →  9.1. Periodicity of physical properties of the elements in Period 3
Open
2
At 450 K phosphorus(chloride, PCl 5, decomposes to form phosphorus(chloride, PCl 3, and chlorine, Cl 2. A dynamic equilibrium is established as shown. PCl 5PCl 3+ Cl 2ΔH = +124 kJ mol–1 The enthalpy change of formation of PCl 3under these conditions is given. ΔHf PCl 3= –320 kJ mol–1 Calculate the enthalpy change of formation of PCl 5under these conditions. Include a sign with your answer. enthalpy change = kJ mol–1 State and explain the effect of increasing temperature on the rate of decomposition of PCl 5. State and explain the effect of increasing temperature on the percentage of PCl 5that decomposes. Explain the meaning of the term dynamic equilibrium and the conditions necessary for it to become established. When 2.00 mol of PCl 5are decomposed at 450 K and 1.00×105 Pa the resulting equilibrium mixture contains 0.800 mol of Cl 2. Calculate the partial pressure of phosphorus(chloride, pPCl 5, in this equilibrium mixture. pPCl 5 = Pa Write the expression for the equilibrium constant, Kp, for the decomposition of PCl 5. Kp = The partial pressures of PCl 3and of Cl 2in this equilibrium mixture are both 2.86×104 Pa. Calculate the value of Kp and state its units. Kp = units =
7. Equilibria  →  7.1. Chemical equilibria: reversible reactions, dynamic equilibrium
Open
3
The elements in Group2 show trends in their properties that are typical of metals. The elements in Group17 show trends in their properties that are typical of non-metals. State and explain the trend in ionisation energy down Group2. State and explain the trend in melting point down Group17. The melting point decreases down Group 2. Explain this trend. Some reactions based on the Group2 metal barium, Ba, are shown. BaXBa(OH)2+ H2Ba(NO3)2+ H2reaction 1 reaction 2 heat in air State the reagent needed for each of reactions 1 and 2. reaction 1 reaction 2 Name X and write an equation for its formation. name equation The Ba(NO3)2, produced by reaction 1, is heated to dryness. The anhydrous solid is then heated strongly and decomposes. Bariumoxide is produced, together with two other products. Identify the two other products of this decomposition reaction and state what would be observed. State what would be observed when excess MgSO4is added to the Ba(OH)2produced in reaction 2. Explain your answer.
10. Group 2  →  10.1. Similarities and trends in the properties of the Group 2 metals, magnesium to barium, and their compounds
Open
4
Some reactions are shown, based on methylpropan-2-ol, (CH3)3COH. (CH3)3COH (CH3)3CBr and (CH3)2CHCH2Br (CH3)2C=CH2 (CH3)3CBr reaction 1 reaction 2 reaction 3 reaction 4 For each of the reactions state the reagent, the particular conditions required, if any, and the type of reaction. For the type of reaction choose from the list. Each type may be used once, more than once or not at all. Each reaction may be described by one or more than one type. hydrolysis dehydration substitution oxidation addition condensation reaction reagentand conditions typeof reaction Draw a diagram to show the SN1 mechanism of reaction 2. Include all necessary charges, dipoles, lone pairs and curly arrows. 1-bromobutane is a structural isomer of the product of reaction 1. Define the term structural isomer and name the three different types of structural isomerism. definition types of structural isomerism 1-bromobutane is treated with the same reagents as in reaction2. Butan-1-ol is formed. Identify the mechanism of this reaction. Explain why this reaction proceeds via a different mechanism from that of reaction2. mechanism explanation  The product of reaction 3, methylpropene, does not show stereoisomerism. Give two reasons why methylpropene does not show stereoisomerism. Methylpropene can be polymerised to form a poly. State the type of polymerisation and draw the repeat unit of the polymer formed from methylpropene. type of polymerisation repeat unit State the difficulty associated with the disposal of poly. Name the two products of reaction 4. name of (CH3)3CBr name of (CH3)2CHCH2Br
14. Hydrocarbons  →  14.2. Alkenes
15. Halogen compounds  →  15.1. Halogenoalkanes
21. Organic synthesis  →  21.1. Organic synthesis
Open