43
The soft solder used for welding and plumbing is alloy of
- A. lead and tin
- B. iron and tin
- C. lead and zinc
- D. iron and zinc
44
A solution which on treatment with hydrochloric acid produces a colourless, odourless gas which turns lime water milky is most likely to be a
- A. trioxonitrate (V)
- B. chloride
- C. trioxocarbonate (IV)
- D. hydroxide
45
When calcium oxide is heated with carbon, the oxide will
- A. be converted to carbide
- B. be converted to the trioxocarbonate (IV) salt
- C. decompose to the metal
- D. melt, producing carbon (IV) oxide
46
An element used in the production of matches is
- A. nitrogen
- B. aluminium
- C. copper
- D. sulphur
47
Trioxonitrate (V) acid is not used for preparing hydrogen gas from metals because it
- A. is strongly oxidizing
- B. is volatile
- C. renders the metal passive
- D. forms a layer of oxide on the metal