How many of the following orders are correct? (a) Be ( OH ) 2 MgCO 3 : Decomposition temperat

Question

How many of the following orders are correct?

(a) $Be (OH)_{2} < Mg (OH)_{2} < Ca (OH)_{2} < Ba (OH)_{2}$ : Basic character

(b) $BaCO_{3} > SrCO_{3} > CaCO_{3} > MgCO_{3}$ : Decomposition temperature

(c) $Na^{+} > Mg^{2 +} > Li^{+} > Be^{2 +}$ : Cationic Size

(d) $Li_{2} CO_{3} > Na_{2} CO_{3} > K_{2} CO_{3} > Rb_{2} CO_{3}$ : Water solubility

(e) $Na_{2} O_{2} < K_{2} O_{2} < Rb_{2} O_{2} < Cs_{2} O_{2}$ : Thermal stability

(f) $LiHCO_{3} < NaHCO_{3} < KHCO_{3} < RbHCO_{3}$ : Thermal stability

(g) $NaF < NaCl < NaBr < NaI$ : Melting point

(h) $Al_{2} O_{3} < MgO < K_{2} O < Na_{2} O$ : Basic nature

TestHub · Accepted Answer

(a) Basic character of Group 2 hydroxides increases down the group because metallic character increases.

(b) Decomposition temperature of Group 2 carbonates increases down the group due to higher stability of larger cations.

(e) Thermal stability of alkali metal oxides increases from Na₂O₂ to Cs₂O₂ because larger cations polarize less.

(f) Thermal stability of bicarbonates also increases down Group 1.

The remaining orders are incorrect due to wrong trends in ionic size, solubility, melting point, or basic nature.

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