Identify anionic ligand from following.

The rate constant is doubled when temperature increases from $27^{\circ} \mathrm{C}$ to $37^{\circ} \mathrm{C}$. What is activation energy in kJ ?

What is the oxidation number of phosphorus in calcium phosphate?

Which of the following forms 2-Methylbut-2-ene on heating with concentrated sulphuric acid?