The sum of the coordination number and oxidation number of the metal M in the complex [M(en)₂(C₂O₄)]Cl is:

The IUPAC name of complex ion, [Fe(CN)₆]^3- is:

1. Hexacyanoiron(III) ion

2. Hexacyanitoferrate(III) ion

3. Tricynoferrate(III) ion

4. Hexacyanidoferrate(III) ion

Cobalt(III) chloride forms several octahedral complexes with ammonia.
A compound among the following that does not give a test for chloride ions with silver nitrate at 25 °C is:

A complex  ion among the following can absorb visible light is:
(At. no. Zn = 30, Sc = 21, Ti = 22, Cr = 24)

1. [Sc(H₂O)₃(NH₃)₃]³⁺

2. [Ti(en)₂ (NH₃)₂]⁴⁺

3. [Cr(NH₃)₆]³⁺

4. [Zn(NH₃)₆]²⁺

Out of ${\mathrm{TiF}}_6^{2-}$, ${\mathrm{CoF}}_6^{3-}$, Cu₂Cl₂ and ${\mathrm{NiCl}}_4^{2-}$(Z of Ti = 22, Co=27, Cu = 29, Ni= 28) the colourless species are:

1. $Ti{F}_6^{2-}$ $and$ $Co{F}_6^{3-}$

2. $C{u}_{2}C{l}_2$ $and$ $NiC{l}_4^{2-}$

3. $Ti{F}_6^{2-}$ $and$ $C{u}_{2}C{l}_2$

4. $Co{F}_6^{3-}$ $and$ $NiC{l}_4^{2-}$

Copper sulphate dissolves in excess of KCN to give:

1. CuCN

2. $\left[Cu\right(CN{)}_4{]}^{3-}$

3. $\left[Cu\right(CN{)}_4{]}^{2-}$

4. $Cu(CN{)}_2$