Acids and Alkalis (paper1) Flashcards
What’s the definitions of an acid
A substance with a ph of less than 7
A substance that turns universal indicator re, orange or yellow
A substance that donates protons in a reaction
Why is sulphuric acid strong
Because it dissociates to form 2 protons in water
What does ph mean
Power of hydrogen
What happens if you increase a hydrogen ion by a factor of 10
The ph increases by 1
What do bases always react with, and what do they make
Acids to make water and a salt
What do carbonates make
CO2
What is CO2 seen as
Bubbles
What’s the sulfate symbol
SO4 2-
Nitrate symbol
NO3 -
Carbonate symbol
CO3 2-
Chloride symbol
Cl -
Bromide symbol
Br -
Sulfide
S2
Oxide symbol
O2 -
Hydroxide
OH-
What ates have that ides don’t
Oxygen
What test is used for hydrogen
Pop test
What is lime water test used for
Test for CO2
What salts are soluble in water
Ammonium salts, sodium, potassium and nitrates
What salts are insoluble
Silver, lead, chlorides, barium
What’s dissociation
When a substance splits into its ions
Why is HCl a strong acid
Because it fully dissociates in water
What defines a weak acid
An acid that doesn’t fully dissociate when dissolved
Name a weak acid
Ethanoic or citric
Define concentration
The amount of a substance dissolved in a volume of water
What is concentration measured in
Moles per decimetre cubed (mol dm -3)
Iodide symbol
I-
When are polyatomic ions formed
When small groups of atoms, held together by covalent bonds, lose or gain electrons
The higher the number of hydrogen ions, the higher the what
Acidity
The higher the number of hydroxide ions, the more what
The more alkaline
What is the concentration equation
Conc= amount dissolved divided by volume of solution
What are bases
Substances that neutralise acids to form a salt and water
During neutralisation, what do hydrogen ions combine with
Oxide ions to form water
How to produce a soluble salt (tin oxide)
1) add excess tin oxide to HCl
2) gently warm mixture to increase rate of reaction
3) filter unreacted solid
4) heat to evaporate water
5) leave to evaporate and crystallise
What process is used to obtain dry soluble salt from a solution
Crystallisation by titration
How to carry out titration
1) carry out titration
2) note exact volume of acid needed to neutralise alkaline
3) use burette to add correct volume of acid without indicator
4) evaporate water
What is effervescence
Hydrogen gas bubbles
All acids form what in aqueous solutions
Hydrogen ions
What are spectator ions
Ions that do not change in a reaction
A loss of electrons is what
Oxidation.
A gain of electrons is what
Reduction.
Acids react with a what to form a salt water and carbon dioxide
Metal carbonates
What is precipitation reaction
A reaction in which soluble substances in a solution cause an insoluble precipitation to form
What is insoluble in water
Silver, lead and lead chlorides, barium, calcium sulphates, most carbonates and most hydroxides
How to prepare insoluble salts
1) Wear eye protection
2) mix 2 solutions in a beaker then filter
3) rinse beaker with distilled water and pour through funnel
4) pour distilled water over precipitate in funnel
5) remove filter paper and dry in warm oven
