2(f) Acids, alkalis and titrations

Question 1

3 types of indicators?

Answer 1

• phenolphthalein
• methyl orange
• litmus

Question 2

what colour is phenolphthalein in acid, neutral and alkali?

Answer 2

ACID: colourless
Neutral: colourless
ALKALI: pink

Question 3

what colour is methyl orange in acid, neutral and alkali?

Answer 3

acid: red
neutral: yellow
alkali: yellow

Question 4

what colour is red litmus in acid, neutral and alkali?

Answer 4

acid: no change
neutral: no change
alkali: blue

Question 5

what colour is blue litmus in acid, neutral and alkali?

Answer 5

acid: red
neutral: no change
alkali: no change

Question 6

pH scale discrption?

Answer 6

goes from, 0-14 (acidic substances have 0 pH)

Question 7

universal indicator?

Answer 7

wide range indicator and can give only an approximate value for pH

Question 8

what is formed when acids are added to water?

Answer 8

they form positively charged hydrogen ions (H+)

Question 9

pH scale description?

Answer 9

goes fro, 0-14 (acidic substances have 0 pH)

Question 10

what is formed when acids are added to water?

Answer 10

• positively charged hydrogen ions (H+)

Question 11

what makes a solution acidic?

Answer 11

the presence of H+ ions

Question 12

what is formed when alkalis are added to water?

Answer 12

negatively charged hydroxide ions

Question 13

what makes an aqueous solution alkali?

Answer 13

the presence negative hydroxide ions

Question 14

neutralization?

Answer 14

this is a reaction that occurs when an acid reacts with an alkali

Question 15

what happens in a neutralisation reaction?

Answer 15

when substances react together in a neutralisation reaction the H+ ions react with the OH- ions to produce water

Question 16

what happens when an acid (hydrochloric acid) reacts with a base (sodium hydroxide)?

Answer 16

• neutralisation reaction
• forms HOH and a salt