• # question_answer In which of the compounds does hydrogen have an oxidation state of -1 A) $C{{H}_{4}}$ B) $N{{H}_{3}}$ C) HCl D) $Ca{{H}_{2}}$

$\overset{+2}{\mathop{Ca}}\,\overset{x}{\mathop{{{H}_{2}}}}\,$ i.e., $2+2x=0$, $x=-1$ $2x=-2$ or $x=\frac{-2}{2}=-1$