Acids, bases and salts Flashcards
What does an indicator do
Test the PH of a solution
If it has a PH of O is it an acid or an alkali
The strongest alkali
Example of a PH of 1
Car Battery acid or stomach acid
Example of a PH of 3
Vinegar, lemon juice
Example of a PH of 4
Acid rain
Example of a PH of 5
Normal rain
Example of a PH of 7
Pure water
Example of a PH of 8
Washing up liquid
Example of a PH of 9
Pancreatic juice
Example of a PH of 11
Soap powder
Example of a PH of 12
Bleach
Example of a PH of 13/14
Caustic acid (drain cleaner)
PH of 0-6 are
ACIDS
PH of 7 is
NEUTRAL
PH of 8-14
ALKALIS
What is an indicator
Change the colour depending on the PH
Acids form
H+ ions in water
An Alkali is a base that
dissolves in water
Alkali forms
OH- to make them alkaline
H+ ions make
acidic solutions
OH- ions make
alkaline
Neutralisation formula
acid + base -> salt + water
Neutralisation formula (terms)
H+ + OH- -> H20
When an acid neutralizes a base
The products are neutral
S =
Solid
L =
Liquid
G =
Gas
aq =
Dissolved in water
Metals react with acids to give
salts
Acids reacting with metals formula
Acid + metals -> salt + hydrogen
The more —- the metal the —– the reaction will go
Reactive
Faster
Copper —-react with dilute acids at all
Does NOT
because its less reactive than hydrogen
Hydrochloric acid will always produce
Chloride salts
Sulphuric acid will always produce
Sulphate salts
Nitric acid always produces
Nitrate salts when NEUTRALISED
Metals that are less reactive than hydrogen
DON’T react with acids
Metal OXIDES and metal HYDROXIDES are
Bases
Some metal oxides and metal hydroxides
Dissolve in water
Things that dissolve in water are called
soluble
Metal oxide formula
Acid + metal oxide -> salt + water
Metal hydroxide formula
Acid + metal hydroxide -> salt + water
Hydrochloric acid and copper oxide =
copper chloride + water
Hydrochloric acid and sodium hydroxide =
sodium chloride + water
Sulphuric acid and zinc oxide =
Zinc sulphate + water
Nitric acid and magnesium oxide =
Magnesium nitrate + water
Nitric acid and potassium hydroxide =
Potassium nitrate + water
Ammonia can be neutralised with HO3 to make
Fertiliser
Ammonia dissolves in water to make an
Alkaline solution
When ammonium reacts with nitric acid you get
Ammonium nitrate
Why is ammonium a good fertiliser
It has nitrogen from two sources, plants need nitrogen proteins
Are chlorides, sulphates and nitrates soluble in water
Yes
Most oxides and hydroxides are
Insoluble in water
How to make a soluble salt using a metal or insoluble base
- Pick the right acid and a metal
- Add the metal, metal oxide or hydroxide to the acid
- It will dissolve
- Filter out the access metal
- Evaporate some of the water, leave to crystallise
How will you know if the acid has been neutralised (when using a metal or insoluble base)
The access solid will sink to the bottom of the flask
How will you know if the acid has been neutralised (when using an alkali)
When the right amount of alkali has neutralised the acid it will go clear
How to make a soluble salt using an alkali
- Add the right amount of alkali
- Use an indicator to show if the reactions finished
- Evaporate to crystallise
How to make a insoluble salt using precipitation reaction
- Pick two solutions that contain the ions you need (lead nitrate solution need lead chloride)
- Mix the solution
- Filter the solution
Method of the reaction of bases and an acid
- Pour 25ml into a measuring cylinder
- Add small amounts of magnesium oxide to acid
- Filter to remove access magnesium oxide
- Pour solution into evaporating dish, leave to crystallise