Question

part 5: ph scale

1. the ph scale measures the concentration of ______ ions in a solution.
2. the scale ranges from to .
3. a solution with a ph less than 7 is ______.
4. a solution with a ph greater than 7 is ______.
5. a solution with a ph of 7 is ______.
6. the lower the ph, the more ______ the solution.
7. the higher the ph, the more ______ the solution.
8. the ph of a substance can be measured using a ____ or ____ paper.

Explanation:

1. The pH scale is defined based on hydrogen ion ($H^{+}$) concentration.
2. By convention, the pH scale ranges from 0 (most acidic) to 14 (most basic).
3. Solutions with pH < 7 have higher $H^{+}$ concentration than $OH^{-}$, classified as acidic.
4. Solutions with pH > 7 have higher $OH^{-}$ concentration than $H^{+}$, classified as basic (alkaline).
5. pH = 7 means $[H^{+}]=[OH^{-}]$, so the solution is neutral.
6. Lower pH implies higher $H^{+}$ concentration, thus more acidic.
7. Higher pH implies lower $H^{+}$ (or higher $OH^{-}$) concentration, thus more basic (alkaline).
8. Common tools for pH measurement are pH meters (electronic) and pH - indicator papers (e.g., litmus paper).

Answer:

1. hydrogen ($H^{+}$)
2. 0; 14
3. acidic
4. basic (alkaline)
5. neutral
6. acidic
7. basic (alkaline)
8. pH meter; pH - indicator