Which of the following is a zero order reaction?

The coagulation of 200 mL of a positive colloid took place when 0.73 g of HCl was added to it without changing the volume much. The flocculation value of HCl for the colloid is

The oxoacid of phosphorus which contains $4 \mathrm{P}-\mathrm{O}-\mathrm{H}, 2 \mathrm{P}=\mathrm{O}$ and one $\mathrm{P}-\mathrm{O}-\mathrm{P}$ bond is

Group 16 elements are also called