acids bases and salts Flashcards
in a solution acids are the source of which ions
hydrogen ions
in a solution alkalis are the source of which ion
hydroxide ions
pH of a neutral solution
7
do acids have pH under or over 7
under
do alkalis have a pH under or over 7
over
litmus paper in acid, and base
acid: red
alkaline: blue
phenolphthalein in acid, neutral and base
acid: colourless
neutral: colourless
alkaline: pink
methyl orange in acid, neutral and base
acid: red
neutral: yellow
alkaline: yellow
universal indicator colour change
red in acid, green in neutral and purple in alkaline
the higher the concentration of hydrogen ions in an acidic solution…
the lower the pH
the higher the concentration of hydroxide ions in alkaline solution…
the higher the pH
when the hydrogen ion concentration increases by a factor of 10, the pH…
goes down by 1
dilute vs concentrated solution
a dilute solution has a low solute concentration and vice versa
weak vs strong acids
a strong acid dissociates completely into hydrogen ions in water, whereas weak acids dissociate only partially
base definition
any substance that reacts with acid to form only a salt and water
alkali defintion
soluble bases
acid + metal
salt and hydrogen
metal (hydr)oxide + acid
salt and water
acid + metal carbonate
salt, water and carbon dioxide
acid + alkali
salt and water
chemical test for hydrogen
squeaky pop test - hold lit splint inside test tube with gas and if squeaky pop noise is made then hydrogen in present
carbon dioxide test
bubble gas through limewater, if turns cloudy, carbon dioxide is present
neutralisation reaction definition
reaction between and acid and a base
how does an acid alkali neutralisation reaction form water
H+ ions from the acid react with OH- ions from the alkali to form water
