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Flashcards in C2e Deck (9)
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1
Q

What is an indicator?

A

-dye that changes colour depending on pH of substances

2
Q

Give some examples of indicators and how they work?

A
  • universal indicator is a combination of dyes, colour change gradually as pH changes, useful for estimating pH of solutions, add a drop of indication to a solution and compare it to a colour chart to work out pH
  • some change colour suddenly at a particular pH
3
Q

What is an acid?

A
  • substance with pH less than 7
  • forms H+ ions in water
  • pH determined by concentration of H+ ions
4
Q

What is a base?

A

-substance with pH greater than 7

5
Q

What is an alkali?

A
  • a base that is soluble in water

- forms OH- ions in water

6
Q

What do acid and ammonia produce?

A

-ammonium salt

7
Q

What do acids and carbonated produce?

A

-carbon dioxide, salt and water

8
Q

What do acids and metal oxide, and acids and metal hydroxide produce?

A

-salt and water

9
Q

What are metal oxides and hydroxides and how do they respond to water and acid?

A
  • some metal oxides and hydroxides dissolve in water
  • these soluble compounds are alkalis
  • some bases that don’t dissolve in water still react with acids