Adding detergents to the water increases its

Options

A. Surface tension
B. Angle of contact
C. Wetting action
D. Viscosity

Answer

To solve the question "Adding detergents to the water increases its...", we need to analyze the effects of detergents on the properties of water. Let's break this down step by step.

### Step 1: Understanding Detergents
Detergents are compounds that typically consist of sodium salts of long-chain fatty acids. Their structure can be represented as R COO⁻ Na⁺, where R is a long hydrocarbon chain. The hydrocarbon part is hydrophobic (water-repelling), while the ionic part is hydrophilic (water-attracting).

**Hint:** Remember that detergents have both hydrophobic and hydrophilic parts, which allows them to interact with water differently than pure water.

### Step 2: Effect on Surface Tension
When detergents are added to water, they disrupt the hydrogen bonding between water molecules. This results in a decrease in surface tension because the detergent molecules position themselves at the surface of the water, with their hydrophobic tails pointing away from the water and their hydrophilic heads interacting with the water molecules.

**Hint:** Consider how the arrangement of molecules at the surface changes when a detergent is introduced.

### Step 3: Decrease in Surface Energy
As the surface tension decreases, the surface energy of the water also decreases. This means that the energy required to increase the surface area of the water is reduced.

**Hint:** Surface energy is related to how much energy is needed to stretch or deform the surface of a liquid.

### Step 4: Increase in Wetting Action
With the decrease in surface tension and surface energy, the wetting action of the water increases. This means that water can spread more easily over surfaces, allowing it to penetrate and wet materials better.

**Hint:** Think about how a liquid behaves on a surface; lower surface tension usually means better spreading and wetting.

### Step 5: Effect on Viscosity
The introduction of detergents can also affect the viscosity of water. As the detergent molecules interact with water, they can reduce the effective viscosity by allowing water molecules to move more freely.

**Hint:** Viscosity is a measure of a fluid's resistance to flow; lower viscosity means the fluid flows more easily.

### Conclusion
In summary, adding detergents to water increases its wetting action and decreases its surface tension and viscosity. Therefore, the correct answer to the question is that adding detergents to water increases its wetting action.

**Final Answer:** Adding detergents to the water increases its wetting action.