Universal Indicator
IGCSE Edexcel Chemistry
2.30 Using universal indicator
Key Concept:
Universal indicator shows a color range that gives an approximate pH value.
Section A: Colors to pH
1. Match the color to the pH range: red, green, purple.
[3]
2. A solution turns universal indicator orange. Is it acidic, neutral or alkaline?
[1]
3. State one advantage of universal indicator over litmus.
[1]
Section B: Estimating pH
4. Complete the table using typical universal indicator colors.
[4]
pH
Color
1
7
10
13
Total marks: 9
Mark Scheme
1.
Red pH 1-3, green pH 7, purple pH 12-14 [3]
2.
Acidic [1]
3.
Gives approximate pH value or shows strength [1]
4.
pH 1 red, pH 7 green, pH 10 blue, pH 13 purple [4]