Which out of `BeCl_2 and CaCl_2` would give acidic solution when dissolved in water?

Explanation

Being a covalent compound and a good Lewis acid, `BeCl_2` forms a hydrated salt,`Be(H_2O)_4Cl_2` . The hydrated ion undergoes hydrolysis in solution producing `H_3O^(+)` . This occurs because the Be-O bond is very strong and so in the hydrated ion this weakens the 0-H bond. Hence, there is a strong tendency to lose protons. For this reason, the aqueous solution of `BeCl_2` is acidic in nature.
`[Be (H_2O)_4]^(2+) + H_2O hArr [Be(H_2O)_3OH]^(+) + H_3O^(+)`
On the other hand, `CaCl_2` is a strongly ionic compound and does not behave as a Lewis acid (size of Ca is relatively large and its octet is filled up). Moreover, since it is a salt of strong acid and strong base, it does not undergo hydrolysis and therefore, its aqueous solution is neutral.