JEE Main 2023 · 24 January · morning · Single correct · +4 / −1
Decreasing order of the hydrogen bonding in following forms of water is correctly represented by
A. Liquid water
B. Ice
C. Impure water
Choose the correct answer from the options given below :
- (a) A = B > C
- (b) B > A > C
- (c) A > B > C
- (d) C > B > A
Answer and solution
Answer (b) B > A > C
Solution
Chemistry ma’am · 4 steps
Count the neighbours each water molecule holds: four in ice, fewer in liquid, fewer still with impurities.
- Ice. In ice, every H₂O molecule is hydrogen bonded to four neighbours in a rigid tetrahedral network. This is the most hydrogen bonding water can have.
- Liquid water. On melting, part of this network breaks, so molecules can move past each other. Liquid water still has many hydrogen bonds, but they keep breaking and re-forming, and on average each molecule has fewer than four.
- Impure water. Dissolved impurities get between the water molecules and interact with them. This disrupts the water-water network further, so impure water has the least hydrogen bonding of the three.
- So. The decreasing order is Ice > Liquid water > Impure water, that is, B > A > C, which is option (b).
The idea to keep. More order means more hydrogen bonds. Melting breaks some of them, and anything dissolved in water breaks still more of the water-water network.
Answer from the NTA final answer key. Solution by PrepWiser.