Acids Flashcards
What is the colour of methyl orange in an acid?
Red
What is the colour of methyl orange in a neutral solution?
Orange
What is the colour of methyl orange in an alkali?
Yellow
What is the colour of universal indicator in an acid?
Red - strong acid
Orange
Yellow -weak acid
What is the colour of universal indicator in a neutral solution?
Green
What is the colour of universal indicator in an alkali?
Blue - weak alkali
Purple - strong alkali
What is the colour of phenolphthalein in acid?
Colourless
What is the colour of phenolphthalein in a neutral solution?
Colourless
What is the colour of phenolphthalein in an alkali?
Pink
What is the colour of red litmus paper in acid?
Red
What is the colour of red litmus paper in a neutral solution?
Red
What is the colour of red litmus paper in an alkali?
Blue
What is the colour of blue litmus paper in acids?
Red
What is the colour of blue litmus paper in a neutral solution?
Blue
What is the colour of blue litmus paper in an alkali?
Blue
What is the hydrochloric acid formula
HCl
What is the sulphuric acid formula?
H2SO4
What is the nitric acid formula?
HNO3
What is the potassium hydroxide formula?
KOH
What is the lithium hydroxide formula?
LiOH
Describe a neutralisation reaction
When the right amount of acid and the right amount of alkali is added together to make a neutral solution
What is the general formula for a neutralisation reaction?
Acid + alkali ——> water + salt
What do all acids contain?
Positive hydrogen ions (H+ ions)
The stronger the acid, the more __ ____ it has.
H+ ions
What do all alkalis contain?
Negative hydroxide ions (OH- ions)
The stronger the alkali is, the more ___ ____ it has.
OH- ions
What is the ionic equation for a neutralisation reaction?
H+ + OH- ——> H2O
What salts do hydrochloric acid produce?
Metal chlorides
What salts do sulphuric acids produce?
Metal sulphates
What salts do nitric acid produce?
Metal nitrates
Sulphuric acid + lithium hydroxide ——> ???
Sulphuric acid + lithium hydroxide ——> lithium sulphate + water
Nitric acid + sodium hydroxide ——> ???
Nitric acid + sodium hydroxide ——> sodium nitrate + water
Hydrochloric acid + aluminium hydroxide ——> ???
Hydrochloric acid + aluminium hydroxide ——> aluminium chloride + water
What is a concentrated acid?
An acid with a high proportion of acid molecules in it
What is a dilute acid?
An acid with a low proportion of acid molecules in it
What is a strong acid?
An acid that completely ionises (dissociates) in water, this means they separate into ions
What is a weak acid?
An acid that only partially ionises (dissociates) in water, this means that some of the acid separates into ions and some stay as the acid
Give an example of a strong acid dissociating
HCl ——> H+Cl-
Magnesium + oxygen ——> ???
Magnesium oxide
Silver + sulphur ——> ???
Silver sulphide
Tin + oxygen ——> ???
Tin oxide
Nickel + sulphur + oxygen ——> ???
Nickel sulphate
Potassium + nitrogen + oxygen ——>???
Potassium nitrate
What is the overall charge of a compound?
0
Acid + metal ——> ???
Salt + hydrogen
Acid + metal oxide ——> ???
Salt + water
Acid + metal hydroxide ——> ???
Salt + water
Acid + metal carbonate ——> ???
Salt + water + carbon dioxide
What is the test for carbon dioxide?
If a limewater solution goes cloudy when gas is put in, then carbon dioxide is present
(Could also use lit splint and if it goes out in the gas then carbon dioxide could be present, but other gasses would also do the same)
What is the test for oxygen?
Oxygen will always relight a glowing splint
Describe titration
- Measure out the alkali using a pipette, put it into a conical flask with a few drops of an indicator eg. Phenolphthalein
- Place the conical flask on top of a white tile, to make it easy to see the colour change
- Fill a burette with acid, using a funnel, then remove the funnel and record your starting volume of acid.
Describe the concentration of H+ ions in an acid as it becomes more acidic
Increases
Describe the concentration of H+ ions in an acid as it becomes more alkali
Decreases
What is a cation?
An ion that is positively charged
What is an anion?
An ion that is negatively charged
What is the formula for magnesium sulphate?
MgSO4
What is the formula for sodium hydroxide?
NaOH