DEMO|PAPER 141-QNS

 

THE PRESIDENT’S OFFICE

REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

MBEYA CITY COUNCIL - NSENGA SECONDARY SCHOOL

TERMINAL EXAMINATIONS

FORM THREE - CHEMISTRY

TIME 2.30HOURS 22/5/2023

INSTRUCTIONS:

1. This paper consist of section A and B and C with a total of ten (14) question

2. Answer all questions in both sections

3. All writing must be in blue or black ink except diagrams which must be in pencil.

4. The following constants may be used:ATOMIC MASSES: C=12 , Fe=55.8, O=16, Na=23,Mg=24, H=1

GMV=22.4dm³/mol

SECTION A (15 Marks)

Answer all question in this section

1.For each of the items (i)-(x),choose the correct answer among the given alternatives and write its correct letter in the box provided.

i.What is the best way of keeping a clean test tube after use ?

1. Keeping it in water

2. Keeping it on a test tube holder

3. Keeping it in a basin for test tubes

4. Keeping it on a test tube rack

ii.Which of the following salts decomposes to its own metal?

1. Sodium chloride

2. Potassium carbonate

3. zinc sulphate

4. silver nitrate

iii.How many moles are produced by 0.69g of sodium?

1. 0.13

2. 3

3. 0.3

4. 0.03

iv. One of the disadvantages of hard water is that it is :

1. Causes increased tooth decay

2. Boils about 300°C

3. Contains harmful minerals

4. Requires a lot of soap for washing

v.Sodium ion Na+, neon atom (Ne), Fluoride ion (F -) and magnesium ion mg2+ and related in that:

1. Some are metals and the others are non-metals.

2. They all have exactly similar electronic configuration.

3. They easily react with each other

4. They are reactive and all of them form compounds

vi.It is for cleaning and drying wounds;

1. Cotton wool

2. Petroleum jelly

3. Bandage

4. Antiseptic

vii. A mixture of two solid substances is commonly heated in the laboratory to produce oxygen such a mixture could be that of:

1. Manganese dioxide and hydrogen peroxide

2. Potassium permanganate and magnesium oxide

3. Mercury (II) oxide and hydrogen peroxide

4. Potassium chlorate and manganese dioxide.

viii. the name given to the colorless and highly flammable gas used in the production of ammonia is;

1. Hydrogen

2. oxygen

3. Carbon Dioxide

4. Helium

ix. Fresh water consists about v…..percentage of the total water on earth;

1. 87

2. 97

3. 3

4. 12

x. Wind is a promising future source of energy because;

1. it is not acceptable in the society

2. it does not involve chemical reactions

3. it is renewable

4. it cannot be seen

xi. most atoms are neutral because

1. the nucleus is only made up of neutrons

2. The neutrons normally have zero charge

3. they have equal numbers of electrons and protons in the shells

4. the number of electrons balances out the number of protons in the atom

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