Page 385 - SUBSEC October 2017_Neat
P. 385
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(g) A student is asked to prepare a buffer solution using an aqueous solution of sodium
hydroxide and one of the aqueous solutions, X(aq) or Y(aq). The dissociation constants
-5
-5
for X is K = 1.8 x 10 , and for Y is K = 1.8 x 10 .
a
b
(i) Define the term ‘buffer solution’.
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[1 mark]
(ii) Which of the solutions, X or Y, would you use with the sodium hydroxide to prepare
a buffer solution? Justify your answer.
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[2 marks]
(iii) Explain how small additions of H and OH ions are accommodated in the buffer DO NOT WRITE IN THIS AREA
–
+
solution prepared above.
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[2 marks] DO NOT WRITE IN THIS AREA
Total 30 marks
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