To compare the acidity of milk and tomato juice, we need to look at their pH levels. Milk has a pH of approximately 6, while tomato juice has a pH of 4. The pH scale is logarithmic, meaning each whole number change on the scale represents a tenfold change in acidity. Therefore, when comparing the pH values:
- A pH of 6 to a pH of 5 is 10 times more acidic.
- A pH of 5 to a pH of 4 is another 10 times more acidic.
So, to find out how much more acidic tomato juice is compared to milk, we multiply these changes: 10 times 10, which equals 100. This means tomato juice is 100 times more acidic than milk.
Thus, the correct choice is d) 100 times more acidic than milk.