$\begin{array}{1 1}(a)\;CH\equiv CH+H_2\quad\underrightarrow{Pd/BaSO_4,S}\quad CH_2=CH_2\\(b)\;CH\equiv CH+H_2O\quad\underrightarrow{Hg^{2+},H^+}\quad CH_3CHO\\(c)\;CH\equiv CH+CH_3COOH\quad\underrightarrow{(CH_3COO)_2Hg}\quad CH_3-CH(OOCCH_3)_2\\(d)\;\text{Both (b) &(c)}\end{array}$
