Chemistry
Arrange the following as per the instruction given in the brackets:
(a) Al, K, Mg, Ca (decreasing order of its reactivity)
(b) N, Be, O, C (increasing order of non-metallic character)
(c) P, Si, F, Be (decreasing order of valence electrons)
Answer
(a) K > Ca > Mg > Al
Reason — According to the electrochemical series metals at the top of the series are most reactive and the reactivity decreases down the group.
(b) Be < C < N < O
Reason — Across a period, left to right in a periodic table, the non-metallic character increases.
(c) F > P > Si > Be
Reason — The valence electrons decreases from right to left in the periodic table.
Related Questions
Identify the cation in each of the following cases:
(a) Ammonium hydroxide solution when added to Solution B gives a white precipitate which does not dissolve in excess of ammonium hydroxide solution.
(b) Sodium hydroxide solution when added to Solution C gives a white precipitate which is insoluble in excess of sodium hydroxide solution.
Fill in the blanks by choosing the correct answer from the brackets:
(a) During electrolysis, the compound …………… in its molten state liberates reddish brown fumes at the anode. [NaCl/PbBr2]
(b) The ion which could be discharged most readily during electrolysis is …………… [Fe2+/Cu2+]
Complete and balance the following equations:
(a) NH4Cl + Ca(OH)2 ⟶
(b) CuSO4 + NH4OH ⟶
(c) Cu + Conc. HNO3 ⟶
State a relevant reason for the following:
(a) Hydrogen chloride gas cannot be dried over quick lime.
(b) Ammonia gas is not collected over water.