Question

Discuss the reactivity of group 15 elements with halogens.

Answer 1

• Elements of the group 15 reacts with halogens to form two series of halides i.e., trihalides (EX₃) and pentahalides (EX₅).
• The pentahalides possess more covalent character due to availability of vacant d orbitals of the valence shell for bonding.
• Nitrogen being second period element, does not have d orbitals in its valence shell, and therefore, does not form pentahalides.
• Trihalides of the group 15 elements are predominantly covalent except BiF₃ . The only stable trihalide of nitrogen is NF₃.

Answer 2

The reactivity series of metals, also known as the activity series, refers to the arrangement of metals in the descending order of their activities. The metals at the top of the reactivity series are powerful reducing agents since they are easily oxidized. These metals tarnish/corrode very easily.

• The data provided by the reactivity series can be used to predict whether a metal can displace another in a single displacement reaction.
• It can also be used to obtain information on the reactivity of metals towards water and acids.

• An important feature of the activity series is that while travelling down the series, the electron-donating ability of the metals reduces.