The structure of $[Cu(H_2O)_4]^{2+}$ ion is

In an octahedral geometry,which pair of $d$-orbitals is involved in $d^2sp^3$ hybridization?

Which of the following complexes has a square planar geometry?

The complex $[Ag(NH_3)_2]^{+}$ has $sp$ hybridization and is a ...... complex.

Assertion $:$ Complex ion $[Co(NH_3)_6]^{2+}$ is readily oxidized to $[Co(NH_3)_6]^{3+}$.
Reason $:$ Unpaired electron in complex ion $[Co(NH_3)_6]^{2+}$ is present in $4p$ orbital.

Which of the following statements is not true for the reaction given below?
$[Cu(H_2O)_4]^{2+} + 4NH_3 \rightleftharpoons [Cu(NH_3)_4]^{2+} + 4H_2O$