Rank the following from most acidic to least acidic.

sample pH
bleach 12.5
coffee 4.2
rainwater 5.4
soap 10.1

My answer: Bleach, Soap, Rainwater,Coffee

Is that right?

No, acidic is below 7.

So is my answer backwards??

Right!

Yes, your answer is correct. To rank the substances from most acidic to least acidic, you need to compare their pH values. The lower the pH value, the more acidic the substance. Here's the process of comparing and ranking the substances based on their pH values:

1. Bleach (pH 12.5): This has the highest pH value among the given substances. Since the pH scale is logarithmic, higher pH values indicate alkalinity rather than acidity. Therefore, bleach is the least acidic substance in the list.

2. Soap (pH 10.1): Soap has a lower pH value compared to bleach but is still on the alkaline side of the pH scale. So, soap is less acidic than bleach but more acidic than the remaining substances.

3. Rainwater (pH 5.4): Rainwater has a lower pH value than both bleach and soap, making it more acidic than them. However, it is still less acidic than coffee.

4. Coffee (pH 4.2): Among the given substances, coffee has the lowest pH value, indicating high acidity. Therefore, it is the most acidic substance in the list.

So, the correct ranking would be: Coffee, Rainwater, Soap, Bleach.