9701_m18_qp_22 - revisedeck

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The graph shows a sketch of the first ionisation energies of six successive elements in the PeriodicTable. The letters are not the symbols of the elements. first ionisation energy A B C D element E F Explain what is meant by the term first ionisation energy. Suggest why the first ionisation energy of B is much less than that of A. P–T are successive elements in Period3 of the Periodic Table. The letters are not the symbols of the elements. On the axes, sketch a graph to show the trend in the atomic radius of the elements P–T. Explain your answer. atomic radius of the element P Q R element S T explanation

1. Atomic structure → 1.4. Ionisation energy

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Carbon and silicon are elements in Group14. C60 and diamond are allotropes of carbon. Describe the lattice structure of solid C60. C60 sublimes (turns directly from solid to gas) at about 800 K. Diamond also sublimes but only above 3800 K. Explain why C60 and diamond sublime at such different temperatures. C60 forms hydrocarbons with similar chemical properties to those of alkenes. One such hydrocarbon is C60H18. State what is meant by the term hydrocarbon. Describe a test to indicate the presence of double bonds between carbon atoms in C60H18. Give the result of the test. test result 0.144 g of C60 was placed in a 100 cm3 container of hydrogen gas at 20 °C and 1.00×105Pa. The container was heated to make the C60 and hydrogen gas react. The reaction occurred as shown in the equation. C60+ xH2C60H2xAfter the reaction, the container was allowed to cool to 20 °C. The pressure decreased to 2.21×104 Pa. All of the C60 had reacted. Name the type of reaction that occurred. Calculate the amount, in moles, of C60 that reacted. amount of C60 = mol Calculate the amount, in moles, of hydrogen gas that reacted with the C60. amount of hydrogen gas = mol Use your answers from and to deduce the molecular formula of the hydrocarbon, C60H2x. If you were unable to calculate the amount of hydrogen gas, assume that 0.00240 mol of hydrogen gas reacted. This is not the correct value for the amount of hydrogen gas that reacted. molecular formula = Silicon shows the same kind of bonding and structure as diamond. State the type of bonding and structure shown by silicon. When silicon reacts with magnesium, Mg2Si forms. Mg2Si is thought to contain the Si4– ion. State the full electronic configuration of the Si4– ion. 1s2 Solid Mg2Si reacts with dilute hydrochloricacid to form gaseous SiH4 and a solution of magnesiumchloride. Write an equation to show the reaction of solid Mg2Si with dilute hydrochloricacid. Include state symbols. Predict the shape of the SiH4 molecule. SiH4 reacts spontaneously with oxygen to produce a white solid and a colourless liquid that turns anhydrous copper(sulfate blue. No other products are formed. Write an equation for the reaction of SiH4 with oxygen. State symbols are not required.

11. Group 17 → 11.2. The chemical properties of the halogen elements and the hydrogen halides

14. Hydrocarbons → 14.2. Alkenes

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Calcium and its compounds have a large variety of applications. Calcium metal reacts readily with most acids. Write an equation for the reaction of calcium with dilute nitricacid. State symbols are not required. When calcium metal is placed in dilute sulfuricacid, it reacts vigorously at first. After a short time, a crust of calcium sulfate forms on the calcium metal and the reaction stops. Some of the calcium metal and dilute sulfuricacid remain unreacted. Suggest an explanation for these observations. Calcium ethanedioate is formed when calcium reacts with ethanedioic acid, (CO2H)2. The compound contains one cation and one anion. Draw the ‘dot-and-cross’ diagram of the cation present in calciumethanedioate. Show all electrons. Draw the displayed formula of the anion present in calciumethanedioate. Calciumchlorate(, Ca(Cl O)2, is used as an alternative to sodiumchlorate(, NaCl O, in some household products. Suggest a use for calciumchlorate(. The chlorate(ion is formed when cold aqueous sodiumhydroxide reacts with chlorine. Write an ionic equation for this reaction. State symbols are not required. The chlorate(ion is unstable and decomposes when heated as shown. Deduce the oxidation number of chlorine in each species. Complete the boxes. 3Cl O– 2Cl – + Cl O3 – oxidation number of chlorine: In terms of electron transfer, state what happens to the chlorine in the reaction in . Calciumlactate is used in some medicines. It forms when lacticacid (2-hydroxypropanoicacid) reacts with calciumcarbonate. C lactic acid H CO2H H3C OH Identify the two other products of the reaction of lacticacid with calciumcarbonate. +1 Two possible methods of making lactic acid are shown. reaction 2 reaction 4 reaction 1 reaction 3 lactic acid C O H H3C C O CO2H H3C C H CH2OH H3C OH C H CN H3C OH C H CO2H H3C OH State suitable reagents and conditions for reactions 1 and 3. reaction reagents and conditions Name the type of reaction that occurs in reaction2. Reaction4 uses NaBH4. Identify the role of NaBH4 in this reaction. Lacticacid has a chiral centre. State what is meant by the term chiral centre.

11. Group 17 → 11.4. The reactions of chlorine

2. Atoms, molecules and stoichiometry → 2.3. Formulas

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Cyclohexane is a colourless liquid used in industry to produce synthetic fibres. A reaction scheme involving cyclohexane is shown. reaction 1 reaction 2 Cl Reaction1 involves a free radical substitution mechanism. State the essential condition required for reaction1 to occur. Complete the table to give details of the mechanism in reaction1. name of step reaction Cl 2 2Cl • propagation + Cl • + • Cl + Cl 2 + Cl • • termination + Cl • • Name the type of reaction that occurs in reaction2. The product of reaction2 is cyclohexene. Cyclohexene can be converted into adipicacid (hexanedioicacid), HO2C(CH2)4CO2H. Identify the reagents and conditions for the conversion of cyclohexene into adipicacid. Suggest three main differences between the infra-red spectra of cyclohexene and adipicacid. In each case, identify the bond responsible and its characteristic absorption range (in wavenumbers).

14. Hydrocarbons → 14.1. Alkanes

14. Hydrocarbons → 14.2. Alkenes

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