(U1) Acid-base Titrations

Question 1

what colour is methyl orange in

1. Acid
2. Neutral
3. Alkali

Answer 1

• red
• yellow
• yellow

Question 2

what colour is Phenolphthalein in

1. Acid
2. Neutral
3. Alkali

Answer 2

• Colourless
• Colourless
• Pink

Question 3

What is a standard solution?

Answer 3

A solution with a known concentration (in moldm^-3)

Question 4

Which indicator(s) is used when titrating:

Strong acid on strong alkali

Answer 4

Methyl orange or phenolphthalein

Question 5

Which indicator(s) is used when titrating:

Strong acid on weak alkali

Answer 5

Methyl orange

Question 6

Which indicator(s) is used when titrating:

weak acid on strong alkali

Answer 6

Phenolphthalein

Question 7

Which indicator(s) is used when titrating:

weak acid on weak alkali

Answer 7

None - have to use pH meter

Question 8

What is a strong acid? (2)

Answer 8

• An acid that fully dissociates in water
• releasing H⁺ ions

Question 9

What is a weak acid? (2)

Answer 9

• An acid that partially dissociates in water
• releasing H⁺ ions

Question 10

What is a weak alkali? (2)

Answer 10

• An alkali that partially dissociates in water
• releasing OH^- ions

Question 11

What is a strong alkali? (2)

Answer 11

• An alkali that fully dissociates in water
• releasing OH^- ions

Question 12

What is the equation for percentage uncertainty?

Answer 12

Percentage uncertainty = absolute uncertainty / measured value X 100

Question 13

What is Molarity (M)?

Answer 13

Concentration in moldm^-3