The chances of formation of hydrate decreases with the decrease in the charge density down the group. This is why, $$Ba{\left( {N{O_3}} \right)_2}$$ does not crystallise with water molecules.
63.
Sodium carbonate solution in water is alkaline due to
A
hydrolysis of $$N{a^ + }$$
B
hydrolysis of $$CO_3^{2 - }$$
C
hydrolysis of both $$N{a^ + }$$ and $$CO_3^{2 - }\,ions$$
Lithium when burnt in air forms a mixture of oxide as well as nitride.
$$4Li + {O_2} \to 2L{i_2}O;$$ $$6Li + {N_2} \to 2L{i_3}N$$
65.
The stability of $${K_2}O,{K_2}{O_2}$$ and $$K{O_2}$$ is in order $${K_2}O,{K_2}{O_2} < K{O_2}.$$ This increasing stability as the size of metal ion increases is due to stabilisation of
A
larger cation by smaller anions through lattice energy effects
B
larger cation by larger anions through lattice energy effects
C
smaller cations by smaller anions through melting point
D
smaller cations by larger anions through melting point.
Answer :
larger cation by larger anions through lattice energy effects
In crystalline sulphates, the coordination number of the ions increases from $$Be$$ to $$Ba$$ and so also the lattice energy hence solubility in $${H_2}O$$ decreases.
68.
$$N{a_2}S{O_3}$$ and $$NaHC{O_3}$$ may be distinguished by treating their aqueous solution with :
69.
An unknown inorganic compound $$(X)$$ loses its water of crystallization on heating and its aqueous solution gives the following reactions :
(i) It gives a white turbidity with dilute $$HCl$$ solution
(ii) It decolourises a solution of iodine in potassium iodide
(iii) It gives a white precipitate with silver nitrate solution which turns black on standing.
Identify the compound $$(X)$$