The complex ion $[Co(en)_2Br_2]^+$ has two optical isomers. Their correct configurations are:

Three arrangements are shown for the complex $[CoBr_2(NH_3)_2(en)]^{\oplus}$. Which one is the wrong statement?

Magnetic moment (spin only) of an octahedral complex having $CFSE = -0.8 \Delta_0$ and surrounded by weak field ligands can be

Give the correct order of initials $T$ or $F$ for following statements. Use $T$ if statement is true and $F$ if it is false.
$(I)$ Sulphide ions react with $Na_2[Fe(CN)_5(NO)]$ to form a purple coloured compound $Na_4[Fe(CN)_5(NOS)]$. In the reaction,the oxidation state of iron changes.
$(II)$ $Pt(IV)$ compounds are relatively more stable than $Ni(IV)$ compounds.
$(III)$ The welding of magnesium can be done in the atmosphere of Helium.
$(IV)$ $LiAlH_4$ on hydrolysis will give $H_2$.

Which of the following statement is/are $TRUE$?

The magnetic moment (spin only) of an octahedral complex having $CFSE = -0.8 \Delta_0$ and surrounded by weak field ligands can be: