Inorganic Chemistry - Acids, Alkalis and Titrations

Question 1

what colour is litmus in acidic and alkaline solutions?

Answer 1

acidic: red
alkaline: blue

Question 2

what colour is methyl orange in acidic and alkaline solutions?

Answer 2

acidic: red
alkaline: yellow

Question 3

what colour is phenolphthalein in acidic and alkaline solutions?

Answer 3

acidic: colourless
alkaline: pink

Question 4

what does the pH scale tell you?

Answer 4

how acidic/alkaline a solution is
pH 0-3: strongly acidic
pH 4-6: weakly acidic
pH 7: neutral
pH 8-10: weakly alkaline
pH 11-14: strongly alkaline

Question 5

how would you measure the approximate pH of a solution?

Answer 5

add universal indicator

Question 6

what colour is universal indicator in acidic and alkaline solutions?

Answer 6

acidic: red
neutral: green
alkaline: purple

Question 7

what is an acid a source of in an aqueous solution?

Answer 7

hydrogen ions

Question 8

what is an alkali a source of in an aqueous solution?

Answer 8

hydroxide ions

Question 9

what are bases?

Answer 9

metal oxides, metal hydroxides and ammonia (NH₃)

Question 10

what happens when acids react with bases?

Answer 10

bases neutralise acids by combining with the hydrogen ions in them:
acid + base → salt + water