(d) $\left\lbrack Ni\left( NH_{3} \right)_{4} \right\rbrack SO_{4}$ $\ \ \ x\ \ \ \ \ 0\ \ \ \ \ \ - 2$ $x + 0 + ( - 2) = 0 \Rightarrow x = + 2\$is valency and 4 is C.N. of Ni
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.