THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL

CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

032/1 CHEMISTRY 1

(For Both School and Private Candidates)

Time: 3 Hours Tuesday November 02, 2004 p.m.

Instructions

1. This paper consists of sections A, B and C.
2. Answer all questions in sections A and B, and two (2) questions from section C.
3. Each question carries 10 marks.
4. Electronic calculators are not allowed in the examination room.
5. Cellular phones are not allowed in the examination room.
6. Write your Examination Number on every page of your answer booklet(s).
7. The following constants may be used.
   Atomic masses: H = 1, C = 12, O = 16, N = 14, Na = 23, S = 32.
   Avogadro’s Number = 6.02 × 10²³
   GMV at STP = 22.4 dm³
   1 Faraday = 96,500 coulombs.

SECTION A (20 marks)

Answer all questions in this section.

1. For each of the items (i) - (x) choose the correct answer from the given alternatives and write its letter beside the item number.

(i) Which of the following sets of laboratory apparatus contains direct measuring items?

1. Crucible, Kipp’s apparatus and volumetric flask
2. Test tube, beaker and gas jar
3. Thistle funnel, separating funnel and beaker
4. Burette, pipette and measuring cylinder
5. Volumetric flask, distillation flask and evaporating dish

(ii) Chloride ions (Cl⁻) differ from chlorine atoms in that the ions have one ---- than the atom.

1. more proton
2. less proton
3. more electron
4. less electron
5. more neutron

(iii) Hard water which is softened just by boiling contains dissolved

1. calcium carbonate
2. calcium chloride
3. magnesium sulphate
4. sodium carbonate
5. calcium hydrogen carbonate

(iv) A wasp sting is alkaline. The solution to help ease the pain by neutralizing the alkali would be one with a pH of:

1. 5
2. 7
3. 8
4. 10
5. 13

(v) Five separate 1 g samples of magnesium were placed in different beakers each containing 50 cm³ of dilute sulphuric acid. The mixture which showed the fastest reaction rate at the start was the one containing magnesium

1. block
2. granules
3. powder
4. ribbon
5. turnings

(vi) The compound CH₃CH₂Cl is named as

1. carbon dichloride
2. methyl chloride
3. methylene chloride
4. ethyl chloride
5. propyl chloride

(vii) Which of the following actions would result into an increase in the temperature of the earth?

1. Increase of distance from the sun
2. Removal of water vapour from the atmosphere
3. Increase of cloud cover
4. Removal of noble gases from the atmosphere
5. Increase of the carbon dioxide content of the atmosphere.

(viii) Denitrifying bacteria

1. remove nitrogen from the atmosphere
2. oxidize nitrogen of the atmosphere
3. add nitrogen into the atmosphere
4. fix nitrogen in the soil through plants
5. add carbon dioxide into the atmosphere.

(ix) During the electrolysis of molten aluminium oxide, 3 Faradays were needed to deposit one mole of aluminium. The number of electrons of aluminium will be

1. 6.02 × 10²³
2. 1.806 × 10²³
3. 180.6 × 10²³
4. 18.06 × 10²³
5. 1806 × 10²³

(x) In plant nutrition nitrogen, phosphorus and potassium are classified as ---- nutrients or elements.

1. micro
2. feeder
3. macro
4. trace
5. supplementary