Question

Which of the following property does not correspond to the order $HI<HBr<HCl<HF$?

• A. Thermal power
• B. Reducing power
• C. Ionic character
• D. Dipole moment

Answer 1

The correct option is B Reducing power

The correct order of the reducing power is $HF<HCl<HBr<HI$. On moving from $HF$ to $HI$, the stability of hydrogen halides decreases. Due to this, reducing power increases on moving down the group.

$HF$ is not a reducing agent and $HI$ is the strongest reducing agent. The trend in the reducing power of hydrogen halides can also be explained on the bases of the increasing size of the halide ions from fluoride to iodide.