AMU Engineering 2018 solved paper Solved Paper

The reducing character of hydrides of group 15 elements increases down the group NH3<PH3<AsH3<SbH3. As we move from NH3 to SbH3, the thermal stability of hydride complex decreases. In other words, their tendency to liberate hydrogen increases and hence their reducing character increases from NH3 to SbH3. Thus, among the given compounds SbH3 is the best reducing agent.