Which of the following pairs of compounds would NOT make a hydrogen bond with each other?

CH3 and H20


H20 and HF


NH4 and HF


H2O and CH3COOH


all of the following would make hydrogen bonds

N, O, and F are the negative ions that make hydrogen bonds. Other atoms are not electronegative enough to do that. Which pair does NOT have N, O, F?

To determine which pairs of compounds would NOT make a hydrogen bond with each other, we need to understand the conditions required for a hydrogen bond to form.

A hydrogen bond occurs when a hydrogen atom is bonded to a highly electronegative atom (such as oxygen, nitrogen, or fluorine) and forms a weak electrostatic interaction with another electronegative atom.

Let's analyze each pair of compounds:

1. CH3 and H2O: In this case, CH3 refers to a methyl group, which does not contain an electronegative atom. Therefore, it cannot form a hydrogen bond with H2O, which has highly electronegative oxygen atoms. So, this pair would NOT make a hydrogen bond.

2. H2O and HF: Both H2O and HF contain highly electronegative atoms (oxygen and fluorine, respectively). Therefore, they can both form hydrogen bonds with each other. So, this pair would make a hydrogen bond.

3. NH4 and HF: NH4 refers to an ammonium ion, which comprises a positively charged nitrogen atom surrounded by hydrogen atoms. While nitrogen is electronegative, the positively charged nature of the NH4 ion prevents it from forming a hydrogen bond with HF. So, this pair would NOT make a hydrogen bond.

4. H2O and CH3COOH: Both H2O and CH3COOH contain highly electronegative atoms (oxygen). Therefore, they can both form hydrogen bonds with each other. So, this pair would make a hydrogen bond.

Based on the analysis, the pair that would NOT make a hydrogen bond is NH4 and HF.