Q.1
Some students heated pieces of limestone in a roaring flame of a bunsen burner. What would they have observed as the reaction was taking place?
  • The limestone spitting and popping
  • The limestone glowing red hot
  • The limestone expanding at first, then going smaller
  • The limestone glowing with an intense white light
Q.2
Calcium carbonate is heated with which of the following substances to make cement?
  • Sand
  • Clay
  • Aggregate (gravel and small pebbles)
  • All of the above
Q.3
Heated limestone was left to cool and when it was cold a few drops of water were added to it. Then a piece of moist litmus paper was touched against it. What was observed?
  • The piece of heated limestone hissed, crumbled and became hot. The litmus paper turned red.
  • The piece of heated limestone hissed, crumbled and became hot. The litmus paper turned blue.
  • The piece of heated limestone turned pale yellow and the litmus paper stayed the same.
  • Nothing happened and the litmus paper stayed the same.
Q.4
A student added some nitric acid to a small quantity of powdered calcium carbonate in a large beaker. Which of the following would have been observed during the experiment?
  • Brown fumes of nitric oxide
  • The calcium carbonate frothed up
  • The calcium carbonate disappeared
  • A fizzing noise was heard
Q.5
What are the products when calcium carbonate thermally decomposes?
  • Calcium and oxygen.
  • Calcium and carbonate.
  • Calcium oxide and oxygen.
  • Calcium oxide and carbon dioxide.
Q.6
What is the formula of calcium carbonate?
  • CaC3
  • CaCO2
  • CaCO3
  • Ca3CO
Q.7
Which of the following statements about limestone is false?
  • It reacts with acid rain and is gradually eroded
  • It is used for making the foundations of roads
  • It is used in the manufacture of cement
  • It is not used in agriculture
Q.8
Which of the following terms best describes calcium oxide?
  • Calcium oxide is an acid
  • Calcium oxide is a base
  • Calcium oxide is neutral
  • Calcium oxide is a salt
Q.9
Calcium oxide is slightly soluble in water and can be used for testing for a gas. What is the gas and what happens to the solution if the gas is present?
  • Hydrogen is the gas and the solution goes blue
  • Oxygen is the gas and the solution gives a green precipitate
  • Nitrogen is the gas and the solution turns a pale straw colour
  • Carbon dioxide is the gas and the solution goes cloudy
Q.10
When calcium carbonate is strongly heated what does it do?
  • It thermally decomposes
  • It optically decomposes
  • It mentally decomposes
  • It does nothing
0 h : 0 m : 1 s