NEET Chemistry The s-Block Elements Questions Solved


Which is not correctly matched?

(1) Basic strength of oxides                                 Cs2O<Rb2O<K2O<Na2O<LiO2

(2) Stability of peroxides                                      Na2O <K2O2<Rb2O2<Cs2O2

(3) Stability of bicarbonate                                   LiHCO3<NaHCO3<KHCO3<RbHCO3<Cs HCO3

(4) Melting Point                                                  NaF<NaCl<NaBr<Nal

 

(A) 1 and 4                                           

(B) 1 and 3

(C) 1 and 2                                           

(D) 2 and 3

(A)

     Basic strength of the oxides increases in the order Li2O<Na2O<K2O<Rb2O<Cs2O. The increase

     in basic strength is due to the decrease in I.E. and increase in electropositive character. The melting

     points of the halides decrease in order NaF>NaCl>NaBr>Nal, as the size of the halide ion

     increases. The decrease in melting point is due to increase the covalent character with increase in the

     size of anion according to Fazan's rule.

Difficulty Level:

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