MARGARET MWACHIYEYA SECONDARY SCHOOL
CHEMISTRY 5070
GRADE 11
NAME: …………………………………………………
CLASS: …...
DATE:
/
/2023
DURATION: 1:30 hours
[40marks]
Instructions to Candidates:
Answer all the question.
Show all you working in the spaces provided.
Copying will result to deduction of marks.
Section A answer grid.
1.
1|Page
2.
3.
4.
5.
6.
7.
8.
9.
10.
SECTION A
1. Which one of the following can be added to hand soap that contains lemon juice to decrease
its PH ?
a)
b)
c)
d)
Ammonia
Baking powder
Lime
Vinegar
2. Which of the following compounds dissolve in water to give a solution with a PH greater
than 7?
a)
b)
c)
d)
Calcium carbonate
Copper (ii) hydroxide
Sodium hydroxide
Sulphur dioxide
3. Which of the following is a characteristic property of alkali in aqueous solution?
a)
b)
c)
d)
They liberate ammonia from ammonium salts
They liberate carbon dioxide from carbonates
They give hydrogen with any metal
They turn universal indicator paper red
4. An amphoteric oxide was added separately to a warm dilute solution of an acid and an alkali.
Which entry in the table is correct?
ACID
a)
b)
c)
d)
ALKALI
Salt formed
Salt formed
No reaction
No reaction
No reaction
Salt formed
Salt formed
No reaction
5. Which salt could be prepared by a method involving crystallization as the final stage?
a)
b)
c)
d)
Barium sulphate
Calcium carbonate
Silver chloride
Sodium nitrate
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6. Which quantity is the same for 1 mole of ethanol and 1 mole of ethane?
a)
b)
c)
d)
Mass
Number of atoms
Number of molecules
Volume of r.t.p
7. What is the mass of oxygen contained in 72g of pure water? (Relative atomic masses :
H=1;O=16)
a)
b)
c)
d)
16g
32g
64g
70g
8.
What has mass equal to that of one mole of water?
a)
b)
c)
d)
24 dm^3 of water
One mole of steam
One molecule of water
Two moles of hydrogen molecules and one mole of oxygen molecules
9. One mole of hydrated copper (ii) sulphate, CuSO4.5H2O is dissolved in water. How many
moles of ions does the solution contain?
a)
b)
c)
d)
1
2
6
7
10. Which of the following statements is true about solubility of salts.
a)
b)
c)
d)
All nitrate salts are insoluble
All chlorides are soluble
All hydrates are insoluble
Potassium salts are all soluble
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SECTION B
1. Define the following terms;
a) Limiting reagent…………………………………………………………………………………………………………………
b) Excess reagent.........................................................................................................................
c) Actual yield…………………………………………………………………………………………………………………………
[6 marks]
2. Benzene reacts with excess of chlorine to give chlorobenzene and hydrochloric acid as the
products. Write a balanced chemical equation of the reaction, including state symbols.
………………………………………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………………………………..
[3 marks]
3. The actual yield is usually less than the theoretical yield. Give one reason to support the
statement above?
………………………………………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………………………………....
[2 marks]
4. Differentiate between a concentrated solution and a dilute solution?
………………………………………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………………………………....
[2 marks]
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SECTION C
1. Calculate the mass of calcium hydroxide required to neutralize 2.5 dm^3 of 0.5 M HCl acid.
Ca(OH)2 (aq) + HCl (aq) → CaCl2 + H2O (l)
[5
marks]
2. Calculate the % by mass of water in sodium carbonate crystals, Na2CO3.10 H2O.
[3 marks]
3. 50.0 cm^3 of 0.105 mol/dm^3 aqueous calcium chloride was treated with an excess of silver
nitrate. White silver chloride was formed and the precipitate weighed after drying. A mass of
1.45g was recorded. What is the percentage yield? [5 marks]
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4. Manganese (IV) oxide reacts with concentrated hydrochloric acid according to the following
equation.
MnO2 (s) + 4HCl (aq) → MnCl2 (aq) + 2H2O (l) + Cl2 (g)
A 4.35g sample of manganese (IV) oxide was added to 1.o mol/dm^3 hydrochloric acid. 48
cm^3 of the acid was needed to react with manganese (IV) oxide in the given sample.
Calculate the percentage purity of Manganese (IV) oxide.
[4 marks]
ALL THE BEST!
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