Read the following and answer any four questions from (i) to (v).
On the basis of reactivity of different metals with oxygen, water and acids as well as displacement reactions, the metals have been arranged in the decreasing order of their reactivities. This arrangement is known as activity series or reactivity series of metals.
The basis of reactivity is the tendency of metals to lose electrons. If a metal can lose electrons easily to form positive ions, it will react readily with other substances. Therefore, it will be a reactive metal. On the other hand, if a meal loses electrons less rapidly to form a positive ion, it will react slowly with other substances. Therefore, such a metal will be less reactive.
(i) Which of the following metals is less reactive than hydrogen?
(a) Copper (b) Zinc (c) Magnesium (d) Lead
(ii) Which of the following metals is more reactive than hydrogen?
(a) Mercury (b) Platinum (c) Iron (d) Gold
(iii) Which of the following metals reacts vigorously with oxygen?
(a) Zinc (b) Magnesium (c) Sodium (d) Copper
(iv) Which of the following represents the correct order of reactivity for the given metals?
(a) Na > Mg > Al > Cu (b) Mg > Na > Al > Cu
(c) Na > Mg > Cu > Al (d) Mg > Al > Na > Cu
(v) Hydrogen gas is not evolved when a metal reacts with nitric acid. It is because HNO3, is a strong oxidising agent. It oxidises the H, produced to water and itself gets reduced to any of the nitrogen oxides (N,O, NO, NO2). But _____________ and _____________ react with very dilute HNO3 to evolve H2 gas.
(a) Pb, Cu (b) Na, K (C) Mg, Mn (d) Al, Zn
Read the following and answer any four questions from (i) to (v).
On the basis of reactivity of different metals with oxygen, water and acids as well as displacement reactions, the metals have been arranged in the decreasing order of their reactivities. This arrangement is known as activity series or reactivity series of metals.
The basis of reactivity is the tendency of metals to lose electrons. If a metal can lose electrons easily to form positive ions, it will react readily with other substances. Therefore, it will be a reactive metal. On the other hand, if a meal loses electrons less rapidly to form a positive ion, it will react slowly with other substances. Therefore, such a metal will be less reactive.
(i) Which of the following metals is less reactive than hydrogen?
(a) Copper (b) Zinc (c) Magnesium (d) Lead
(ii) Which of the following metals is more reactive than hydrogen?
(a) Mercury (b) Platinum (c) Iron (d) Gold
(iii) Which of the following metals reacts vigorously with oxygen?
(a) Zinc (b) Magnesium (c) Sodium (d) Copper
(iv) Which of the following represents the correct order of reactivity for the given metals?
(a) Na > Mg > Al > Cu (b) Mg > Na > Al > Cu
(c) Na > Mg > Cu > Al (d) Mg > Al > Na > Cu
(v) Hydrogen gas is not evolved when a metal reacts with nitric acid. It is because HNO3, is a strong oxidising agent. It oxidises the H, produced to water and itself gets reduced to any of the nitrogen oxides (N,O, NO, NO2). But _____________ and _____________ react with very dilute HNO3 to evolve H2 gas.
(a) Pb, Cu (b) Na, K (C) Mg, Mn (d) Al, Zn
(i) Option (a), Copper is placed below hydrogen in activity series therefore, it is less reactive than hydrogen.
(ii) Option (c), Iron is placed above hydrogen in activity series therefore, it is more reactive than hydrogen.
(iii) Option (c), Sodium is very reactive in compare with Zn, Mg, and Cu. So, it reacts vigorously with oxygen.
(iv) Option (a), Na > Mg > Al > Cu
(v) Option (c), Mg, Mn
Only two metals having a capacity to react even with dilute acids like Nitric acid to release Hydrogen gas. Those metals are:- Magnesium (Mg) and Manganese (Mn).
(ii) Option (c), Iron is placed above hydrogen in activity series therefore, it is more reactive than hydrogen.
(iii) Option (c), Sodium is very reactive in compare with Zn, Mg, and Cu. So, it reacts vigorously with oxygen.
(iv) Option (a), Na > Mg > Al > Cu
(v) Option (c), Mg, Mn
Only two metals having a capacity to react even with dilute acids like Nitric acid to release Hydrogen gas. Those metals are:- Magnesium (Mg) and Manganese (Mn).
