Identify neutral ligand from following?

Which from following is used as catalyst in Fisher Tropsch process for the synthesis of gasoline?

For a reaction,

$\mathrm{A}+\mathrm{B} \longrightarrow$ product, it is found that rate law is $\mathrm{r}=\mathrm{k}[\mathrm{A}]^{1.5}[\mathrm{~B}]^{2.5}$. What is the order of reaction?

Which of the following ion exihibits maximum power of coagulation for positively charged Sol ?