Question

The table below shows the color of three indicators at different pH values.
Indicator | pH=0 | pH=2 | pH=4 | pH=6 | pH=8 | pH=10 | pH=12 | pH=14
Litmus paper | Red | Red | Red | Red | Blue | Blue | Blue | Blue
Phenolphthalein | No Change | No Change | No Change | No Change | No Change | Pink | Pink | Pink
Thymol blue | Red | Red | Yellow | Yellow | Yellow | Blue | Blue | Blue

Answer 1

The table you have provided illustrates the color changes of three indicators (Litmus paper, Phenolphthalein, and Thymol blue) at different pH levels. Here's a summary of how each indicator behaves across the pH scale:

### 1. **Litmus Paper**
- **pH 0 to 4**: Red
- **pH 6 to 8**: Blue
- **pH 10 to 14**: Blue
- **Transition**: Litmus paper changes from red (acidic) to blue (basic) around pH 6.

### 2. **Phenolphthalein**
- **pH 0 to 4**: No Change (Colorless)
- **pH 6 to 8**: No Change (Colorless)
- **pH 10 to 14**: Pink
- **Transition**: Phenolphthalein remains colorless until approximately pH 10, where it turns pink in basic conditions.

### 3. **Thymol Blue**
- **pH 0 to 2**: Red
- **pH 4 to 6**: Yellow
- **pH 8 to 14**: Blue
- **Transition**: Thymol blue shows a transition from red (acidic) to yellow between pH 2 and 6 and then turns blue in basic conditions starting around pH 8.

### Summary
- **Litmus Paper** is useful for determining whether a solution is acidic or basic, shifting from red to blue at pH 6.
- **Phenolphthalein** is effective for identifying strong bases, changing from colorless to pink around pH 10.
- **Thymol Blue** provides a wider range of color changes across pH levels, useful for identifying acidic, neutral, and basic solutions, changing colors at different ranges (red to yellow, yellow to blue).

These indicators help in assessing the acidity or alkalinity of a solution based on their respective color changes at specific pH ranges.