Question

1. a substance with a pH of 3
2. a substance with a pH of 10
3. a substance with a pH of 7
4. an indicator
5. a scale that represents the concentration of H30+, 0-14

A.) phenolphthalein
B.) base
C.) pH scale
D.) neutral
E.) acid

Answer 1

1. E
2. B
3. D
4. A
5. C

Answer 2

Answer: 1. a substance with a pH of 3: acid  

2. a substance with a pH of 10:  base

3. a substance with a pH of 7: neutral

4. an indicator: phenolphthalein  

5. a scale that represents the concentration of $H_3O^+$, 0-14: pH scale

Explanation:-

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration and pOH is calculated by taking negative logarithm of hydroxide ion concentration.

On the pH scale ranging from 0 to 14 , Acids have pH ranging from 0 to 6.9, bases have pH ranging from 7.1 to 14 and neutral solutions have pH equal to 7.

$pH=-\log [H^+]$

$pOH=-log[OH^-]$

$pH+pOH=14$

Indicators show a change or appearance in color at particular pH. Phenolphthalein is one such acid base indicator which shows pink color in basic solutions and colorless in acidic solutions.