01.
For each of the following items, choose the most
correct answer from the given alternatives and write its letter beside the item
number in your answer sheet.
i)
Oxygen forms about ________ % by volume of the air
we breathe.
A. 21
B. 78
C. 0.05
D. 26
ii)
The breakdown of a chemical compound into elements
or smaller compounds is:
A. Composition
B. Decomposition
C. Cracking
D. Compound
iii)
2H2O2
(aq) A 2H2O (l) + O2
(g) , a letter A represents:
A. Manganese IV
oxide
B. Heat
C. Hydrogen peroxide
D. Hydrogen oxide
iv)
A substance that alters the rate of chemical
reaction but remain chemically unchanged at the end of reaction is:
A. A catalyst
B. Water
C. Oxidizing agent
D. Reducing agent
v)
The colourless gas formed when potassium chlorate is
decomposed by heating is:
A. Carbon dioxide
B. Oxygen
C. Hydrogen
D. Nitrogen
Answers:
|
i
|
ii
|
iii
|
iv
|
v
|
|
|
|
|
|
|
02.
Draw a well labeled diagram to show the preparation
of oxygen gas in the laboratory from the decomposition of hydrogen peroxide
using manganese IV oxide as the catalyst.
03.
When a metal burn in air ___________ oxide is formed
while when a non-metal burns in air _________ oxide is formed.
04.
List four (4) physical properties of oxygen gas.
05.
List any four (4) uses of oxygen gas.
06.
Kachima was conducting an experiment in the
laboratory, he burnt a metal X which was observed to burn with a bright white
flame and at the end of combustion white powder was formed. From this
experiment;
i.
What is the name and chemical formula of metal X?
ii.
Write the chemical formula and name of the product
formed.
07.
Complete and balance the following equations:
i. 2H2O2 (aq) MnO2 --->
ii. 2KClO3(s) --->
08.
What is the function of manganese IV oxide (MnO2)
in the reaction in 07 (i)?
01. OXYGEN
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Oleh
uprising scientists
