Candidate's Examination Number . . . . . . . . . . . . .

THE UNITED REPUBLIC OF TANZANIA, NATIONAL EXAMINATIONS COUNCIL

FORM TWO SECONDARY EDUCATION EXAMINATION, 2011

0032 CHEMISTRY

Time: 2½ HOURS

INSTRUCTIONS

1. This paper consists of sections A, B and C.
2. Answer ALL questions.
3. Write your examination number at the top right corner of every page.
4. ALL writing must be in black or blue ink EXCEPT diagrams which must be in pencil.
5. Cellphones and calculators are not allowed in the examination room.
6. The following atomic masses may be used: 

• H = 1, O = 16, C = 12, Na = 23, S = 32, Ca = 40.

SECTION A (10 MARKS)

1. Write the letter of the correct answer from the given alternatives in the box provided.

(i) Isotopes are atoms of the same element that have different:

1. Atomic number
2. Electron arrangement
3. Mass number
4. Protons

(ii) When substance A and substance B react to produce a new substance C, the reactants A and B are said to:

1. Be miscible
2. Form a mixture
3. Form a solution
4. Undergo chemical change

(iii) In the formula of the compound F₂K₃, the valences of F and K are respectively:

1. 2 and 3
2. 3 and 2
3. 4 and 6
4. 6 and 4

(iv) The process by which water is converted into water vapour or steam is called:

1. Condensation
2. Evaporation
3. Precipitation
4. Transpiration

(v) In the Bunsen burner, a sooty flame is most likely to be formed when the:

1. Air holes are fully closed
2. Air holes are opened
3. Flame is noisy
4. Flame is smaller and hotter

(vi) The best way to separate a mixture of iodine and iron filings is by:

1. Decantation
2. Evaporation to dryness
3. Fractional distillation
4. Sublimation

(vii) The choice of the source of heat depends on the:

1. Colour of the flame
2. Quantity of heat produced
3. Substance to be burned or boiled
4. Type and shape of flame

(viii) When oxygen combines with metals they:

1. Form metallic oxides
2. Form precipitates
3. Rust
4. Sublime

(ix) The pair of elements which is most likely to form a covalent bond when they react together is:

1. Carbon and oxygen
2. Magnesium and potassium
3. Nitrogen and aluminium
4. Sodium and oxygen

(x) A calcium ion (Ca²⁺) differs from a calcium atom (Ca) because a calcium ion has:

1. Less electrons
2. Less protons
3. More electrons
4. More neutrons