Name: Class:
MARANATHA PRIVATE SECONDARY SCHOOL
2019 MOCK EXAMINATION
CHEMISTRY
PAPER 1 (100 MARKS)
Date:
Time allowed: 2 hours
INSTRUCTIONS
1. This paper contains 10 printed pages. Please check.
2. Fill in your name at the top of each page
3. This paper contains two sections A and B. answer all questions in the
space provided.
4. Use of electronics calculator is allowed
5. The maximum number of marks for each answer is indicated against
each question.
Name: Class:
SECTION A (70 Marks)
1.a. State any two ways of disposing chemical wastes in the laboratory.
(2 marks)
b. Explain why hot acidic wastes should not dispose in sucks
(2 marks)
2. Study the experimental set up below and answer the questions that follow
----
- - - -- - - - - - water
sodium
a. Name the gas that is collected at X
(1 mark)
b. Give the test for this gas
(1 mark)
c. What is the name of the resulting solution when sodium dissolves in water?
Name: Class:
(1 mark)?
(2 Explain why it is not advisable to prepare this gas using potassium instead of sodium in the same set up
(1 mark)
3. An athlete was accused of using the drug THG to enhance his running performance since his urine tested
positive. Describe how you would use chromatography to confirm this.
(4 marks)
4.a. Nitrogen reacts with hydrogen as shown in the equation below
N2 + 3H 2 ⇋ 2NH3
i. Identify the process represented by the equation
(1 mark)
ii. State one catalyst that could be used in the equation
(1 mark)
iii. Explain why high pressure is used in this reaction
(1 mark)
iv. What is the relevance of the compromised temperature of 4500C in this reaction?
.
(1 mark)
Name: Class:
b. In contact process, Sulphur dioxide and oxygen react in the presence of a catalyst to form compound X
i. name the catalyst used in this process
(1 mark)
ii. what is compound X that is formed in the process
(1 mark)
5.i. Define ionic bond character in covalent compounds
(1 mark)
ii. State any two properties of giant covalent structures
(2 marks)
iii. Explain why graphite conducts electricity while diamond does not
(2 marks).
6.i. What is meant by empirical formula
(1 mark)
ii. Work out the empirical formula as a compound has the following percentage composition by mass as elements;
C= 40%, H= 6.67%, and O= 53.33% (RAM C= 12, H= 1, O= 16)
Name: Class:
(5 marks)
Names: Class:
7. Balance the following equation
PCl5 (s) + H2O (l) → H5PO4 (aq) + HCl (aq)
(4 marks)
b. Calculate the number of atoms in the following (RAM S= 32, Na= 23)
i. 92g of sodium (2 marks)
Name: Class:
ii. 12g of Sulphur (2 marks)
8. Compound X contains carbon and hydrogen atoms only 0.84g of X was burned completely in air. This produced
2.64g of carbon dioxide and 10g of water. Work out the empirical formula of compound X. (RAM C= 12, O= 16, H= 1)
(6 marks)
Name: Class:
9. The table shows electron configuration of some elements represented by letters. MNOP and Q. Study the table
and answer the question that follow
Element Electron configuration
M 2.7
N 2.8.2
O 2.8.5
P 2.2
Q 2
Name: Class:
a. What is the atomic number of element N?
(1 mark)
b. Which element has atoms with greatest mass
(1 mark)
c. What type of bonding would be found between atoms of;
i. M?
(1 mark)
ii. M and P?
(1 mark)
iii. M and O?
(1 mark)
Name: Class:
10. magnesium metal reacts with chlorine according to the following equation
2Mg (s) + O2 → 2MgO
If 40g of magnesium and 40g of chlorine are available for the reaction, determine;
i. The limiting reagent
(4 mark)
ii. The mass of magnesium chloride formed
Name: Class:
(4 mark)
11.a. Define an acid in terms of the Bronsted and Lowry theory.
(1 mark)
b. In the following equation; HSO4 + OH- SO2 + H2O
identify any one conjugate acid/ base pair
(2 marks)
Name: Class:
d. A 50ml sample of sodium hydroxide solution is titrated with a 2m solution of Hydrochloric acid. The titration
requires 25ml of the acid solution to reach the end point. What is the molarity of the base solution?
(6 marks)
Name: Class:
SECTION B (30 Marks)
11.a. three test tubes were set up as shown to investigate rusting of iron. After one-week rusting was observed
in the tube C but not in the tubes A, and B
stopper
Oil layer air
Iron nail
Boiled water
Anhydrous calcium chloride
i. Why is anhydrous calcium chloride placed in the test tube?
.
ii. Why is water in the test tube B boiled?
.
iii. Using relevant chemical equations describe how rusting occurs
.
(8 marks)
12.a. Define the term global warming
b. State any two greenhouse gases
Name: Class:
(2 marks)
c. Describe how ozone layer is depleted by Chlorofluorocarbons CFC gases
(7 marks)
Name: Class:
e. Coper is a very good conductor of electricity but its conductivity is reduced by impurities. Describe how impure
copper can be purified using electrolysis.
END OF PAPER
