Which one of the following properties is not generally exhibited by ionic compounds ?
Ionic compounds conduct electricity only in the molten state and not in solid state.
Which of the following metals are obtained by electrolysis of their chlorides in molten state ?
Na and Ca are obtained by electrolysis of their molten chlorides. These are very reactive metals. The oxides of very reactive metals cannot be reduced with carbon. The highly reactive metals are extracted by the electrolytic reduction of their molten chloride.
Which one of the following metals do not react with cold as well as hot water ?
The metal sodium, calcium and magnesium are highly reactive to water and make their hydroxides.
Iron is a less reactive metal and does not show any reaction while treated with cold as well as hot water but will react with steam and form metal oxides and hydrogen gas.
Generally, metals are solid in nature. Which one of the following metals is found in liquid state at room temperature ?
All metals are solid at room temperature except for mercury. Mercury(hg) metal exists as a liquid at room temperature.
Which among the following statements is incorrect for magnesium metal ?
Magnesium is low in reactivity in the reactivity series than sodium and potassium, it reacts with hot water and steam.
Metals are refined by using different methods. Which of the following metals are refined by electrolytic refining ?
Electrolytic refining is used for metals like Cu, Zn, Ag, Au etc. The method to be used for refining an impure metal depends on the nature of the metals as well as on the nature of impurities present in it. So, metals Au (gold) and Cu (copper) are refined by electrolytic refining.
Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same ?
(i) Good thermal conductivity
(ii) Good electrical conductivity
(iv) High melting point
The properties that are expected from a metal for use as cooking utensils are good thermal conductivity and high melting point.
During electrolytic refining of zinc, it gets
During electrolytic refining of zinc (Zn), the pure zinc metal is deposited on cathode. It is connected to the negative terminal of the battery. Zn2+ ions from the solution move towards the negatively charged cathode. Hence Zn is deposited on the cathode.
Silver articles become black on prolonged exposure to air. This is due to the formation of
Silver reacts with H2S present in the air to form Ag2S which is black in colour.
An alloy is
An alloy is a mixture of two metals (or a metal and a non-metal) mixed homogeneously.