**Stronger Hydrogen Bond: CH3CHFCH3 and CH3COOH or H2O and H2O2?**

**Introduction:**
Hydrogen bonding is a special type of dipole-dipole interaction between a hydrogen atom and an electronegative atom such as nitrogen, oxygen, or fluorine. It occurs when the hydrogen atom is covalently bonded to a highly electronegative atom and interacts with another electronegative atom nearby. In this context, we will compare the strength of hydrogen bonds in two pairs of compounds: CH3CHFCH3 and CH3COOH, and H2O and H2O2.

**CH3CHFCH3 and CH3COOH:**
1. **CH3CHFCH3:** This compound is 2,2-difluoropropane, which consists of carbon, hydrogen, and fluorine atoms. The hydrogen bonding in this compound occurs between the hydrogen atom attached to a carbon atom and the electronegative fluorine atoms nearby. However, the electronegativity of fluorine is lower than that of oxygen, which reduces the strength of the hydrogen bond.

2. **CH3COOH:** This compound is acetic acid, which contains carbon, hydrogen, and oxygen atoms. The hydrogen bonding in acetic acid occurs between the hydrogen atom attached to the carboxylic acid group (COOH) and the oxygen atom of another acetic acid molecule. Oxygen is more electronegative than fluorine, resulting in a stronger hydrogen bond.

Therefore, the pair CH3COOH exhibits a stronger hydrogen bond compared to CH3CHFCH3 due to the higher electronegativity of oxygen.

**H2O and H2O2:**
1. **H2O:** Water is a well-known compound that exhibits strong hydrogen bonding. It consists of oxygen and hydrogen atoms. The hydrogen bonding in water occurs between the hydrogen atoms of one water molecule and the oxygen atom of another water molecule. Oxygen, being highly electronegative, attracts the shared electrons towards itself, resulting in a partial negative charge on oxygen and partial positive charges on the hydrogen atoms.

2. **H2O2:** Hydrogen peroxide is a compound that contains hydrogen and oxygen atoms. The hydrogen bonding in hydrogen peroxide occurs between the hydrogen atoms attached to oxygen and the oxygen atoms of other hydrogen peroxide molecules. Similar to water, oxygen is highly electronegative in hydrogen peroxide as well.

Although hydrogen peroxide also exhibits hydrogen bonding, the strength of the hydrogen bond in water is higher due to the presence of two hydrogen atoms, compared to hydrogen peroxide, which has only one hydrogen atom available for hydrogen bonding.

Therefore, the pair H2O exhibits a stronger hydrogen bond compared to H2O2 due to the presence of two hydrogen atoms available for hydrogen bonding.

**Conclusion:**
In conclusion, the pair CH3COOH (acetic acid) exhibits a stronger hydrogen bond compared to CH3CHFCH3 (2,2-difluoropropane) due to the higher electronegativity of oxygen compared to fluorine. Similarly, the pair H2O (water) exhibits a stronger hydrogen bond compared to H2O2 (hydrogen peroxide) due to the presence of two hydrogen atoms available for hydrogen bonding in water.

First pair. Bcoz in it H is attached to more electro-ve F which will attract the electrons more strongly.