Which among the following group-$15$ elements does $NOT$ react with concentrated sulphuric acid?

Which of the following statements is correct regarding $AsH_3$?

Among the hydrides $NH_3, PH_3,$ and $BiH_3$, the hydride with the highest boiling point is $X$ and the hydride with the lowest boiling point is $Y$. What are $X$ and $Y$ respectively?

Which one of the following is formed (mainly) when red phosphorus is heated in a sealed tube at $803 \,\,K$?

Which of the following is a tetrabasic acid?

Which of the following pentahalides is $NOT$ formed?