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The elements phosphorus, sulfur and chlorine are in Period 3 of the Periodic Table.
Table 1.1 shows some properties of the elements P to Cl.
The first ionisation energy of S is not shown.
(a) (i) Complete Table 1.1 to show the number of electrons in the 3p subshell and the total number of unpaired electrons in an atom of P, S and Cl.
[2]
(ii) Construct an equation to represent the first ionisation energy of P.
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[1]
(iii) Three possible values for the first ionisation energy of S are given.
{
1000 \text{kJ mol}^{-1} \quad 1160 \text{kJ mol}^{-1} \quad 1320 \text{kJ mol}^{-1}
}
Circle the correct value.
Explain your choice by comparing your chosen value to those of P and Cl.
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[4]
(b) $\text{P}^{3-}$, $\text{S}^{2-}$ and $\text{Cl}^{-}$ have the same number of electrons.
(i) Give the full electronic configuration of $\text{P}^{3-}$.
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[1]
(ii) State the trend in ionic radius shown by $\text{P}^{3-}$, $\text{S}^{2-}$ and $\text{Cl}^{-}$.
Explain your answer.
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[2]
(c) A student does three tests on separate samples of NaCl(aq).
Complete Table 1.2 with the observations the student makes in each test.
[3]
(d) PCl$_3$ shows similar chemical properties to PCl$_5$.
PCl$_3$ has a melting point of 1°C and a boiling point of 106°C.
PCl$_3$ reacts vigorously with water, forming misty fumes and an acidic solution.
(i) Explain how the information in (d) suggests the structure and bonding of PCl$_3$ is simple covalent.
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[2]
(ii) Construct an equation for the reaction of PCl$_3$ with water.
PCl$_3$ + .................................. $\rightarrow$ ......................................................
[1]
(iii) PCl$_3$ contains a double covalent bond between P and O.
Complete the dot-and-cross diagram, in Fig. 1.1, to show the bonding in PCl$_3$.
Show outer shell electrons only.
[2]
(e) PCl$_3$(g) forms when PCl$_3$(g) reacts with O$_2$(g).
$$2\text{PCl}_3(g) + \text{O}_2(g) \rightarrow 2\text{POCl}_3(g)$$
Table 1.3 gives some relevant data.
(i) Define enthalpy change of formation, $\Delta H_f$.
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[2]
(ii) Calculate the bond energy of P=O in PCl$_3$ using the data in Table 1.3.
Show your working.
bond energy of P=O = ................................................ kJ mol$^{-1}$
[2]
538
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519
(a) (i) State the variation in solubilities of group 2 hydroxides. ........................................................................................................ [1]
(ii) State what is observed in reaction 1.
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(iii) Suggest a reactant for reaction 2.
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(iv) Identify A.
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(v) Ba(OH)_2 is made by the reaction of Ba with water. Write an equation for this reaction.
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(b) The mineral barytocalcite contains both BaCO_3 and CaCO_3. Both compounds decompose on heating.
(i) State which compound decomposes first when barytocalcite is heated. Explain your answer.
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(ii) Construct an equation for the complete thermal decomposition of barytocalcite. The formula of barytocalcite is BaCa(CO_3)_2.
BaCa(CO_3)_2 .................................................................................. [1]
(c) Ba(OH)_2 is used to hydrolyse organic compounds.
Fig. 2.2 shows the reaction of B with Ba(OH)_2, followed by acidification.
Draw the structures of the organic products of the process shown in Fig. 2.2. [Image_Fig2.2] [3]
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507
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Potassium chlorate, $KClO_3$, is widely used as an oxidising agent and to make $O_2(g)$.
(a) Define oxidising agent.
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(b) $KClO_3(s)$ decomposes when heated. $MnO_2(s)$ catalyses the exothermic decomposition reaction.
Complete and label the diagram in Fig. 3.1 to show the effect of $MnO_2(s)$ on the decomposition of $KClO_3(s)$.
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(c) When $KClO_3$ is heated without a catalyst, $KClO_4$ and $KCl$ form.
$$4KClO_3 \rightarrow 3KClO_4 + KCl$$
Explain why this reaction is described as a disproportionation reaction.
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(d) Molten $KClO_3$ reacts with glucose, $C_6H_{12}O_6$:
$$4KClO_3 + C_6H_{12}O_6 \rightarrow 6CO_2 + 6H_2O + 4KCl$$
$KClO_3$ melts at 630K. At this temperature, both $CO_2$ and $H_2O$ are gases.
(i) Use the ideal gas equation to calculate the volume, in m$^3$, of one mole of gas at 630 K and $1.00 \times 10^5$ Pa.
Show your working. Give your answer to 3 significant figures.
volume of 1 mol of gas = ........................................................... m$^3$ [1]
(ii) 5.00 g of $C_6H_{12}O_6$ reacts completely with molten $KClO_3$.
Use your answer to (d)(i) to calculate the total volume of gas released at 630 K and $1.00 \times 10^5$ Pa in this reaction.
(If you were unable to answer (d)(i), use 0.0463 m$^3$ in this question. This is not the correct answer to (d)(i).)
total volume of gas released = ........................................................... m$^3$ [2]
(e) The structure of glucose, $C_6H_{12}O_6$, is shown in Fig. 3.2.
(i) Complete Table 3.1 to identify the number of primary, secondary and tertiary alcohol groups present in the structure shown in Fig. 3.2.
[Table_1]
type of alcohol group | primary | secondary | tertiary
number of groups
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(ii) Separate samples of aqueous glucose are tested with the reagents shown in Table 3.2.
Complete Table 3.2 with the observation for each reaction.
Write “no reaction” if applicable.
[Table_2]
reagent and conditions | observation with glucose
acidified $KMnO_4(aq)$ and warm
Fehling’s reagent and warm
alkaline $I_2(aq)$ and warm
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(iii) There are many structural isomers of $C_6H_{12}O_6$.
Define structural isomers.
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Compounds C and D are alkenes with the same molecular formula, $C_5H_{10}$.
(a) (i) Give the systematic name of D.
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(ii) Explain why C and D do not show geometrical (cis/trans) isomerism.
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(iii) Draw the structure of a molecule that is a positional isomer of C and D.
[1]
(iv) Give the structural formula of the compound formed when D reacts with $H_2(g)$ in the presence of a Pt catalyst.
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(v) C can form an addition polymer.
Draw the structure of one repeat unit of this addition polymer.
[1]
(b) The mass spectrum of C shows a molecular ion peak at $m/e = 70$. This peak has a relative intensity of 48.7.
The relative intensity of the [M+1] peak is 2.7.
Show that this information is consistent with the molecular formula of C.
[2]
(c) C and D both react with HBr.
(i) C reacts with HBr to form E.
Complete the diagram in Fig. 4.2 to show the mechanism for this reaction.
Draw the structure of the organic intermediate.
Include charges, dipoles, lone pairs of electrons and curly arrows, as appropriate.
[3]
(ii) D reacts with HBr to produce F, a chiral bromoalkane.
Draw the structure of F.
[1]
(iii) Explain why the reaction of HBr with C and D produces different major products.
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(d) C can be used to form H.
One possible synthesis of H is shown in Fig. 4.5. Different portions of C are used in reactions 1 and 3. Some of the products are then combined to produce H.
Fig. 4.5 does not show any of the inorganic products of the reactions.
Complete Table 4.1 with the reagents and conditions required for each of the reactions shown in Fig. 4.5.
[Table_1]
[3]
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