Question

Which of the following hydrogen bonds is likely to be the weakest?

• A. C$-$H$\cdots$O
• B. N$-$H$\cdots$O
• C. O$-$H$\cdots$O
• D. O$-$H$\cdots$F

Hint:

Using a simple frame or just bolding for the box Key Points: H-bond strength depends on the polarity of the X$-$H bond. Higher electronegativity of X leads to a more polar X$-$H bond and a stronger H-bond. Electronegativity order: F>O>N >> C. C$-$H bonds are generally considered nonpolar or weakly polar, leading to very weak H-bonds (if any).