JEE Advanced levelSingle correct optionDifficulty 3 of 3ph153
XeFX4 accepts a fluoride ion from a strong fluoride donor to form a planar anion. The F−Xe−F angle between adjacent fluorines in this anion is
A108∘
B72∘
C90∘
D120∘
Answer: B
XeFX4+FX−XeFX5X−, which has 5 bond pairs and 2 lone pairs (sp3d3). The lone pairs are axial, so five F atoms lie in a regular pentagon around Xe. The angle between adjacent F atoms = 360∘/5=72∘.