scieoce mcqs

1. Which of the following
is the most reactive
among halogens?
a) fluorine
b) chlorine
c) bromine
d) iodine
2. Which one of the
following was used as a
chemical weapon in the
First World War?
a) carbon monoxide
b) hydrogen cyanide
c) mustard gas
d) water gas
3. Which one of the
following has the
highest fuel value?
hydrogen
b) charcoal
c) natural gas
d) gasoline
4. Which one of the
following is used as an
anti-freeze for the
automobile engines?
a) propyl alcohol
b) ethanol
c) methanol
d) ethylene glycol
5. Which one of the
following gases is used
for the purification of
water?
a) oxygen
b) ammonia
c) chlorine
d) carbon dioxide
6. What is the chemical
name of baking soda?
a) sodium bicarbonate
b) sodium nitrate
c) sodim carbonate
d) potassium nitrate
7. Which one of the
following is present in
common toothpastes
as an abrasive?
a) calcium oxide
b) calcium carbonate
c) calcium fluoride
d) calcium chloride
8. Which one of the
following chemicals is a
food preservative?
a) sodium carbonate
b) sodium bicarbonate
c) sodium benzoate
d) sodium thiosulphate
9. Which one of the
following is present in
gobar gas?
a) carbon dioxide
b) ethane
c) methane
d) hydrogen
10. Which are the two
of the most common
elements in the earth's
crust?
a) nitrogen and oxygen
b) nitrogen and silicon
c) carbon and oxygen
d) silicon and oxygen
11. Which one of the
following is a
greenhouse gas?
a) oxygen
b) hydrogen
c) carbon dioxide
d) nitrogen
12. Fire extinguishers
release which of the
following gas?
a) hydrogen
b) nitrogen
c) carbon dioxide
d) carbon monoxide
13. Which one of the
following gases present
in the upper
atmosphere protects
the earth from harmful
ultraviolet radiations?
a) carbon dioxide
b) ozone
c) nitrogen
d) oxygen
14. Which one of the
following is the main
culprit in the thinning of
ozone layer in the
earth's upper
atmosphere?
a) carbon dioxide
b) chloroflurocarbons
c) nitrogen
d) oxygen
15. Which one of the
following is present in
the emission from
'unleaded petrol'?
a) carbon monoxide
b) carbon dioxide
c) hydrocarbons
d) ethylene
Answers
1.
fluorine
2. mustard gas
3. hydrogen
4. ethanol
5. chlorine
6. sodium bicarbonate
7. calcium fluoride
8. sodium benzoate
9. methane
10. silicon and oxygen
11. carbon dioxide
12. carbon dioxide
13. ozone
14. chloroflurocarbons
15. hydrocarbons