Chem Reaction of Acids Flashcards
A lower pH is…?
more acidic
A higher pH is…?
more alkaline
What colors are low pH
red/orange
What colors are high pH
blue/purple
What is the reaction between acids and bases called?
Neutralisation
What is equation for acid + base
acid + base —> salt + water
Method for titration
1) Use pipette transfer 25cm3 of sodium hydroxide to conical flask
2) Add 2 or 3 drops of indicator
3) Use a funnel to fill burette with acid of known concentration. Record initial volume
4) Place conical flask on white tile so can see colour change more clearly
5) Add acid to alkali until solution is neutral. Swirl at same time
6) Read volume of acid added from burette
What colour is phenolphthalein in acids?
colourless
What colour pheno in alkalis
pink
What colour is litmus in acids?
red
what colour is litmus in alkali?
blue
What colour is methyl orange in acids?
red
What colour is methyl in alkali?
yellow
What happens to strong acids in water?
They ionise completely. All the acids dissociate to relase H+ ions
What happens when acids ionise?
They produce H+ ions
What happens to weak acids in water?
They don’t fully ionise and only a small proportion of acid particles dissociated to produce H+ ions.
What happens to the pH if you increase the hydrogen ion concentration
Decreases
What happens to the pH if you decrease the hydrogen ion concentration?
Increases
What’s the equation for acid + metal oxide
acid + metal oxide —> salt + water
Equation for acid + metal hydroxide
acid + metal hydroxide —-> salt + water
Equation for acid + metal carbonate
acid + metal carbonate —-> salt + water + carbon dioxide
Making salts
1) Gently heat acid in beaker until almost boiling
2) Use spatula add small amounts of copper oxide to acid in excess
3) Filer to remove unreacted copper oxide
4) place copper oxide solution into evaporating basin. Heat gently over a beaker of boiling water
5) water will evaporate and crystallisation will occur
Ionic Equation for neutralisation reaction
H+(aq) + OH-(aq)—> h20(l)
