cameroon gce O level June 2023 chemistry 1

cameroon gce O level June 2023 chemistry 1

cameroon gce O level June 2023 chemistry 1

A change of state from solid to liquid is called
A Melting
B Freezing
C Condensation
D Evaporation
2. What is the effect of acid falling into streams?
A The water is treated
B The water is neutralised
C The water becomes too acidic for aquatic life
D The PH of the water does not change much
3. The electronic configuration of an element, M,
is 2,8,4. To which group of the Modern Periodic Table is the element found?
A IV
B III
C II
D VIII
4. Identify a common gas produced when nitrates
of groups I and II are strongly heated.
A NO
B N20
C 02
D NO2
5. Which general molecular formula below
represents a family of organic compounds that will decolourize aqueous bromine?
A CnH2,
B CnH2r,÷20
C Cntl2n+2
D CF,H2r102
6. Which of the following ions doesn’t have a
noble gas electronic structure?
A 13A13+
B liNa+
C J2Mg÷
D 16 S2-
7. Consider the following organic reaction.
CH3COOH + C2HSO 1-1-1147 CH3COOC2H5 + H2O Name the reaction type.
A Dehydration
B Condensation C Hydration
D Esterification
8. Identify an element which is soft and can be
cut with a knife.
A Ca
B Mg C Na
D Cu

9. State the reagent and reaction condition that
are needed to convert ethene to ethane
A H2/Fe Catalyst
B I-12/Ni Catalyst C 02/Fe Catalyst
D 02/N i Catalyst
10. Which of the following metals will liberate
hydrogen gas from hydrochloric acid?
A Sodium
B Copper C Silver
D Gold
11. The PH of a solution is 8.6. This implies that
the solution is
A Amphoteric
B Neutral
C Acidic
D Basic
12. Which of the elements below exist as diatomic
molecule?
A Chlorine
B Lithium
C Sodium
D Magnessium
13. 12g of a salt dissolves in 40g of water at 10°C.
What will happen to the solubility when the temperature increases to 20°C.
A It decreases
B It remains constant
C It increases then decreases
D It increases
Questions 14 — 15 concerns the following information on a gas Z. A gas Z is usually
collected in a laboratory by downward delivery
14. Identify a gas which could be Z
A CO
B SO,
C H2
D NH3
15. What property of gas Z makes it to be
collected as stated?
A Gas Z is soluble in water
B Gas Z is less denser than water C Gas Z is denser than air
D Gas Z is lighter than air

3

16. Select a component of air whose percentage
composition by volume is 21%.
A Carbondioxide
B Oxygen
C Nitrogen
D Argon
17. Identify a suitable method that can be used to
obtain pure salt sample from a salt solution. A Fractional distillation
B Decantation
C Filtration
D Evaporation to dryness
S. Which of the following gases is used in fire
extinguishers?
A Chlorine gas
B Carbon dioxide
C Hydrogen gas
D Carbon monoxide
19. Give an element that is usually stored under
paraffin oil.
A Zinc
B Magnesium
C Calcium
D Potassium
20. Select a statement that is TRUE of the
halogens? .
A They have high boiling points
B They exist as single atoms at room temperature
C They are good conductors of electricity
D Their ions form precipitates with”AgNO3
21. Which of the following is NOT true of the
Group I elements?
A They burn to give basic oxides
B They react with dilute acid evolving oxygen gas
C Reactivity increases down the group
D They show a +1 oxidation state in their compounds
22. Which of the following from air is not separated
by factional distillation.
A N2
B 02
C CO,
D H2
23. Why is phosphorus stored under water?
A It is insoluble in water
B It is poisonous
C To prevent it from catching fire in air
D It dissolves in water

24. Which of the following reaction does NOT
occur?
A Br2(0+ 2KC1*) 2KBr + C12(,)
B CI 2(g) 2KBr(aq) KC1 + Br2(g)
C F2(g) 2NaClog) NaF + C12(,)
D C12(0 + 2NaI(,) 2NaCI + I2(g)
25. Name one natural source of clean water?
A Lakes
B Oceans
C Springs
D Streams
26. Select a compound below that when heated,
produces a brown gas.
A NaNO2
B NaNO3 C Ca(NO3)2
D KNO3
27. List the main elements found in fertilizers
A Na,K,Ca
B K,N,Mg
C K,N,P
D Na,N,K
28. What is the mass of 0.3moles of ammonia
(RMM = 17)?
A 5.1g
B 0.018g C 17.3g
D 56.67g
29. Give one bi-product in the electrolysis of brine
which is used as rocket fuel.
A Chlorine gas
B Oxygen gas C Hydrogen gas
D Nitrogen gas
30. What is the empirical formula of a compound
that contains 80% carbon and 20% hydrogen?
A CH
B C2H6 C C21-14
D CH3
31. A carbonate of an element, X, on heating
produces the oxide of X and CO,. The element X is most likely to be
A Na
• B Ca C K