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A-Level ChemistryYear 2020Q8

20 8 This question is about the thermal stability of Group 1 and Group 2 nitrates and carbonates. (a) Complete the equations for the thermal decomposition of sodium nitrate, NaNO3 , and for the thermal decomposition of calcium nitrate, Ca(NO3)2 . State symbols are not required. (2) NaNO3 → Ca(NO3)2 → (b) The thermal stability of Group 1 nitrates increases down the group. The decomposition temperatures of some Group 1 nitrates are shown. Name Formula Decomposition temperature / K sodium nitrate NaNO3 653 potassium nitrate KNO3 673 caesium nitrate CsNO3 687 Explain why the thermal stability of caesium nitrate is greater than that of sodium nitrate. (3) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... 21 (c) Calcium carbonate is thermally decomposed during the manufacture of cement. (i) Write an equation, including state symbols, for the thermal decomposition of calcium carbonate. (1) (ii) Name all the types of bond present in calcium carbonate. (1) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (iii) Give a reason, in terms of the bonding, why a high decomposition temperature is required. (1) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (Total for Question 8 = 8 marks) TOTAL FOR PAPER = 80 MARKS 22 BLANK PAGE 23 BLANK PAGE 24

Paper Source:8CH0_01_que_20201007.pdf

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Exam Specification Info

This question is part of the UK A-Level Chemistry syllabus. In the actual exam, structured questions typically require linking specific keywords to gain full marks. Applaa helps you drill these topics.

Syllabus levelAdvanced Level (A-Level)

SubjectChemistry

Official MarksVariable (2–6 marks)