The mixture of conc. $HCl$ and potassium chlorate on heating gives

Which of the following halogen acids is least acidic?

Which reaction has a positive value of $\Delta G^o$?

$POCl_3$ is prepared by the reaction of:
$(I)$ $P_4 + SO_2Cl_2 \to$
$(II)$ $P_4 + SOCl_2 \to$
$(III)$ $PCl_5 + SO_2 \to$
$(IV)$ $PCl_5 + C_2H_5OH \to$

Which of the following is the correct increasing order of the reducing power of halide ions?

Which of the following gives chlorine upon heating?