43
For iron to rust, there should be present?
- A. oxygen
- B. moisture
- C. carbondioxide
- D. oxygen and moisture
- E. oxygen, moisture and carbondioxide
44
Methane is member of the homologous series called?
- A. alkenes
- B. alcohols
- C. esters
- D. alkanes
- E. alkynes
45
The oxidation number of manganese in KMnO4 is?
- A. +1
- B. +3
- C. +5
- D. +7
- E. +2
46
An example of a strong electrolyte is?
- A. ethyl acetate
- B. ethanol
- C. glucose
- D. sodium formate
- E. formic acid
47
When glowing splint is inserted into the mouth of a jar containing a gas, the splint is extinguished. The gas gives a white precipitate when passing into barium hydroxide. The gas is?
- A. methane
- B. hydrogen chloride
- C. hydrogen
- D. nitrogen
- E. carbondioxide
48
When a bottle of Coca-Cola is opened, bubbles of evolve. The gas is?
- A. hydrogen
- B. carbon monoxide
- C. carbon dioxide
- D. sulphur oxide
- E. chlorine
49
An element X has 127 neutrons and 82 electrons.
Its atomic number is?
- A. 209
- B. 105
- C. 45
- D. 82