Lesson 2 - Chemical Indicators

Question 1

What is common between oranges, lemons and limes?

Answer 1

They are all sour, are weak acids, contain citric acid, are all citrus fruits.

Question 2

Describe the oxidising symbol briefly

Answer 2

There is a ball, and a fire outlining it.

Question 3

Describe the irritant symbol

Answer 3

An exclamation mark

Question 4

Describe the flammable symbol

Answer 4

It is a flame/fire

Question 5

Describe the corrosive symbol

Answer 5

There is a hand, and it shows vials being poured above it.

Question 6

Agree or disagree, an indicator tells you whether a solution is an acid or an alkali.

Answer 6

Agree

Question 7

Agree or disagree, different indicators change colour at different pH levels

Answer 7

Disagree

Question 8

What is an indicator?

Answer 8

An indicator is a substance that has different colours in an acid or alkali

Question 9

What colours do acids turn? (Hint: litmus paper, universal indicator)

Answer 9

Acids turn blue litmus paper or universal indicator red.

Question 10

What colours do alkalis turn? (Hint: litmus paper, universal indicator)

Answer 10

Alkalis turn red litmus paper and universal indicator blue

Question 11

Can litmus paper tell how strong/weak/neutral a substance is?

Answer 11

No, you cannot

Question 12

An unknown substance was poured into a test tube. The red litmus paper turned blue. Was this an acid or alkali?

Answer 12

Alkali

Question 13

What does pH stand for? (Hint: it includes one of the elements..)

Answer 13

pH = power of hydrogen

Question 14

True or false, do all acids contain hydrogen?

Answer 14

True, all acids contain hydrogen