Question
Which substance should be pure for the intended use?
- a drug for curing disease
- limestone for iron extraction
- petroleum for fractional distillation
- water for washing a car
Answer/Explanation
Ans:
A
Question
A student measures the time taken for 2.0 g of magnesium to dissolve in 50 cm3 of dilute sulfuric acid.
Which apparatus is essential to complete the experiment?
- stop-clock
- measuring cylinder
- thermometer
- balance
A 1, 2 and 4 B 1 and 2 only C 1 and 4 only D 2, 3 and 4
Answer/Explanation
Ans:
A
Question
Which substance is used as a bleach in the manufacture of paper?
A carbon dioxide
B nitrogen dioxide
C silicon dioxide
D sulfur dioxide
Answer/Explanation
Ans: D
Question
What is an industrial use of calcium carbonate?
A cracking of hydrocarbons
B manufacture of aluminium
C manufacture of cement
D purification of water
Answer/Explanation
Ans: C