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Flashcards in C2e Deck (9):

What is an indicator?

-dye that changes colour depending on pH of substances


Give some examples of indicators and how they work?

-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


What is an acid?

-substance with pH less than 7
-forms H+ ions in water
-pH determined by concentration of H+ ions


What is a base?

-substance with pH greater than 7


What is an alkali?

-a base that is soluble in water
-forms OH- ions in water


What do acid and ammonia produce?

-ammonium salt


What do acids and carbonated produce?

-carbon dioxide, salt and water


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

-salt and water


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

-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