Choose the correct statements about the hydrides of group 15 elements. A. The stability of the hydrides decreases in the order NH 3 > PH 3 > AsH 3 > SbH 3 > BiH 3 B. The reducing ability of the hydrides increases in the order NH 3 < PH 3 < AsH 3 < SbH 3 < BiH 3 C. Among the hydrides, NH 3 is strong reducing agent while BiH 3 is mild reducing agent. D. The basicity of the hydrides increases in the order NH 3 < PH 3 <

Step-by-step solution

On moving down the group from N to Bi , the atomic size increases. Consequently, the electron density on the central atom decreases and the basic strength decreases. With an increase in size, the M - H bond becomes weaker, hence, the thermal stability decreases down the group. The highest bond length will have less bond energy, indicating that it is a strong reducing agent. On moving down the group, bond strength of M–H bond decreases, which reduces the thermal stability but increases reducing nature of hydrides, H