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fluorine. [2]
(ii) Write an equation to represent the third ionization energy of magnesium. Explain
why the third ionization energy of magnesium is higher than that of fluorine. [3]
(f) (i) Explain why sodium has a lower melting point than magnesium. [3]
(ii) By referring to their structure and bonding explain why magnesium oxide has a
higher melting point than sulfur dioxide. [3]
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8. (a) (i) Define the term pH. [1]
(ii) A 25.0 cm3 sample of 0.100 mol dm-3 hydrochloric acid was placed in a conical
flask, and 0.100 mol dm-3 sodium hydroxide is added until a total of 50.0 cm3 had
been added. Sketch a graph of pH against volume of NaOH(aq) added, clearly
showing the volume of NaOH(aq) needed for complete reaction and the pH values
[4]
at the start, the equivalence point and finish.
(iii) The experiment in (a) (ii) was repeated, but with a 25.0 cm3 sample of 0.100 mol dm-3
ethanoic acid in the conical flask instead of the hydrochloric acid. Use information
from Table 16 of the Data Booklet to calculate the pH at the start of the experiment.
[5]
State the approximate pH value at the equivalence point.
(b) (i) Describe how an indicator, HIn, works. [3]
(ii) Name a suitable indicator for the reaction between ethanoic acid and sodium
hydroxide. Use information from Table 17 in the data booklet to explain your choice. [2]
(c) (i) Identify two substances that can be added to water to form a basic buffer solution. [1]
(ii) Describe what happens when a small amount of acid solution is added to the buffer
solution prepared in (i). Use an equation to support your explanation. [2]
(d) Define the terms Brønsted-Lowry acid and Lewis acid. For each type of acid, identify one
example other than water and write an equation to illustrate the definition. [5]
(e) Predict and explain whether an aqueous solution of 0.10 mol dm-3 AlCl3 will be acidic,
[2]
alkaline or neutral.
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9. (a) Given the structures of the repeating units of the polymers below, identify the monomers
from which they are formed.
(i) [1]
(ii) [1]
(iii) [2]
(b) Describe the essential difference between the structures of monomers that form addition
polymers and the structures of monomers that form condensation polymers. [2]
(c) Draw and name an isomer of ethanoic acid, CH3COOH. [2]
(d) (i) State the name of the reagent and the conditions required to convert ethanoic acid
to methyl ethanoate. Write an equation for the reaction. [3]
(ii) Discuss two physical properties that differ for ethanoic acid and methyl ethanoate. [2]
(iii) Deduce the ratios of the areas under the peaks in the 1H NMR spectrum of ethanoic
[2]
acid and methyl ethanoate.
(e) (i) There are four structural isomers with the formula C4H9Cl, one of which is
optically active, CH3CHClCH2CH3. State the name of this isomer and explain why
it is optically active. [2]
(ii) Outline how the two optical isomers can be distinguished experimentally. [2]
(iii) Draw the structure of the three other structural isomers of C4H9Cl. [2]
(iv) Identify one isomer in (iii) that undergoes a substitution reaction mainly by a SN 2
mechanism. [1]
(v) Write the SN 2 mechanism for the reaction that occurs when the isomer identified
in (iv) is warmed with aqueous sodium hydroxide. Use curly arrows to present the
movement of electron pairs. [3]
2206-6102
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zanotowane.pl doc.pisz.pl pdf.pisz.pl chiara76.opx.pl
fluorine. [2]
(ii) Write an equation to represent the third ionization energy of magnesium. Explain
why the third ionization energy of magnesium is higher than that of fluorine. [3]
(f) (i) Explain why sodium has a lower melting point than magnesium. [3]
(ii) By referring to their structure and bonding explain why magnesium oxide has a
higher melting point than sulfur dioxide. [3]
2206-6102
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11 M06/4/CHEMI/HP2/ENG/TZ0/XX
8. (a) (i) Define the term pH. [1]
(ii) A 25.0 cm3 sample of 0.100 mol dm-3 hydrochloric acid was placed in a conical
flask, and 0.100 mol dm-3 sodium hydroxide is added until a total of 50.0 cm3 had
been added. Sketch a graph of pH against volume of NaOH(aq) added, clearly
showing the volume of NaOH(aq) needed for complete reaction and the pH values
[4]
at the start, the equivalence point and finish.
(iii) The experiment in (a) (ii) was repeated, but with a 25.0 cm3 sample of 0.100 mol dm-3
ethanoic acid in the conical flask instead of the hydrochloric acid. Use information
from Table 16 of the Data Booklet to calculate the pH at the start of the experiment.
[5]
State the approximate pH value at the equivalence point.
(b) (i) Describe how an indicator, HIn, works. [3]
(ii) Name a suitable indicator for the reaction between ethanoic acid and sodium
hydroxide. Use information from Table 17 in the data booklet to explain your choice. [2]
(c) (i) Identify two substances that can be added to water to form a basic buffer solution. [1]
(ii) Describe what happens when a small amount of acid solution is added to the buffer
solution prepared in (i). Use an equation to support your explanation. [2]
(d) Define the terms Brønsted-Lowry acid and Lewis acid. For each type of acid, identify one
example other than water and write an equation to illustrate the definition. [5]
(e) Predict and explain whether an aqueous solution of 0.10 mol dm-3 AlCl3 will be acidic,
[2]
alkaline or neutral.
2206-6102 Turn over
1112
12 M06/4/CHEMI/HP2/ENG/TZ0/XX
9. (a) Given the structures of the repeating units of the polymers below, identify the monomers
from which they are formed.
(i) [1]
(ii) [1]
(iii) [2]
(b) Describe the essential difference between the structures of monomers that form addition
polymers and the structures of monomers that form condensation polymers. [2]
(c) Draw and name an isomer of ethanoic acid, CH3COOH. [2]
(d) (i) State the name of the reagent and the conditions required to convert ethanoic acid
to methyl ethanoate. Write an equation for the reaction. [3]
(ii) Discuss two physical properties that differ for ethanoic acid and methyl ethanoate. [2]
(iii) Deduce the ratios of the areas under the peaks in the 1H NMR spectrum of ethanoic
[2]
acid and methyl ethanoate.
(e) (i) There are four structural isomers with the formula C4H9Cl, one of which is
optically active, CH3CHClCH2CH3. State the name of this isomer and explain why
it is optically active. [2]
(ii) Outline how the two optical isomers can be distinguished experimentally. [2]
(iii) Draw the structure of the three other structural isomers of C4H9Cl. [2]
(iv) Identify one isomer in (iii) that undergoes a substitution reaction mainly by a SN 2
mechanism. [1]
(v) Write the SN 2 mechanism for the reaction that occurs when the isomer identified
in (iv) is warmed with aqueous sodium hydroxide. Use curly arrows to present the
movement of electron pairs. [3]
2206-6102
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