In Cro_4^(2-) ion, Cr is ............. hybridised. | CLASS 12 | D AND F-BLOCK ELEMENTS | CHEMIS...

In acidic medium, H_(2)O_(2) changes Cr_(2)O_(7)^(2-) ion to CrO_(5) . The oxidation states of Cr in Cr_(2)O_(7)^(2-) and CrO_(5) are respectively :

Assertion : In acidic medium, K_2Cr_2O_7 exists as Cr_2O_7^(2-) (orange) while in basic medium it is converted to CrO_4^(2-) (yellow). Reason : K_2Cr_2O_7 is hygroscopic in nature and changes colour on reaction with water.

Assertion : Solution of Na_(2) CrO_(4) in water is intensely electrons. Reason : Oxidation state of Cr in Na_(2) CrO_(4) is + VI .

In which of the following there is a change in oxidation number ? (a) An aqueous solution of CrO_(4)^(2-) is acidified. (b) SO_(2) gas is passed through acidified Cr_(2)O_(7)^(2-) solution. (c) Cr_(2)O_(7)^(2-) solution is made alkaline. (d) CrO_(2)Cl_(2) is dissolved in NaOH.

On addition of a solution containing CrO_4^(2-) ions to the solution of Ba^(2+), Sr^(2+) , and Ca^(2+) ions, the precipitate obtained first will be of