Question

Given the following pairs of molecules, hydrogen bonds can be found in which ones?

CH4 and CH3
CH4 and NaCl
H₂O and NH₂
CH₂Cl and HI

Answer 1

First, it would be helpful to consider this acronym to help remember what elements hydrogen bonds form with:

Hydrogen bonds have FON!

H-bonds form between hydrogen atoms bonded to either fluorine, oxygen, or nitrogen atoms.

In the third answer choice, H2O and NH2, the hydrogens are bonded to O and N, respectively. Oxygen and nitrogen belong to FON, and thus form H-bonds. All of the other answer choices do not form H-bonds because the hydrogen is not bonded to any of the FON elements.

Therefore, H2O and NH2 is the correct answer.