Acids, Bases + Salts Flashcards
What kind of ions do acids produce in water
H+ ions
What are the “rules” for solubility of salts?
K+, Na+,NH4+ = all salts soluble
NO3 − = all salts soluble
SO4 2− = all soluble, except Pb2+, Ba2+, Ca2+
Cl − = all soluble, except Pb2+, Ag+
CO3 2− = all INsoluble, except K+, Na, NH4+
What is the general equation for a neutralisation reaction? What is the general equation for when an acid and alkali react?
Acid + Base → Salt + Water
Acid + Alkali → Salt + Water
What is the general equation for
the reaction between metal
carbonate and acid?
Metal Carbonate + Acid → Salt + Water + Carbon Dioxide
What is the general equation for the reaction between metal oxide and acid?
Metal Oxide + Acid → Salt + Water
What is a redox reaction?
A reaction where both oxidation and reduction occurs
How are oxidation and reduction defined in terms of electron transfer?
Oxidation – loss of electrons.
Reduction – gain of electrons.
What is oxidation/reduction in terms of oxygen?
- Oxidation is the addition of oxygen to a substance.
- Reduction is the loss of oxygen from a substance.
What is an oxidising agent? What is a reducing
agent?
- An oxidising agent is a species that gets reduced in a redox reaction (gains electrons; causes the oxidation of another substance).
- A reducing agent is a species that gets oxidised in a redox reaction (loses electrons; causes the reduction of another substance).
What do acids and alkalis produce in aqueous solutions?
- Acids produce hydrogen ions (H+)
- alkalis produce hydroxide ions (OH-)
What are bases?
- Bases are compounds that neutralise acids to produce a salt
What are acids?
- Acids are substances that produce hydrogen ions in aqueous solutions
What are alkalis?
- Alkalis are soluble bases that produce hydroxide ions in aqueous solutions
State the general equation for a neutralisation reaction in a short, ionic form
H(+) + OH(−) → H2O
What is a strong acid? What is a weak acid?
- Strong acid is completely ionised in aqueous solution
- weak acid is only partially ionised in aqueous solution
What happens to pH as
concentration of H+ increases?
- It decreases as the more concentrated the acid, the lower the pH is
What is a concentrated acid and
what is a dilute acid? Is this the
same as a strong and weak acid?
- Concentrated has more moles of acid per unit volume of water than dilute (dilute refers to solutions of low concentrations).
- Not the same - concentration is not the same thing as the strength of an acid.
- Strength refers to whether the acid is completely ionised in water (strong) or only partially (weak).
An acid is a proton ….
donor
A base is a proton ….
acceptor
What is a salt
- a metal or ammonium ion
- with a negative ion from an acid
example of the use of ammonia as a base
● HCl + NH3 -> NH4Cl
Describe an experiment to prepare a pure, dry sample of a soluble salt, starting from an insoluble reactant
● add excess insoluble base to the acid
● filter to remove unreacted base
● heat the solution so that water evaporates and crystals of the salt remain
Describe an experiment to prepare a pure, dry sample of a soluble salt, starting from an insoluble reactant
STEP BY STEP
- measure acid into beaker
- warm acid to speed up reaction
- add solid until no more disappears
- filter to remove excess solid
- filtrate contains solution of soluble salt
- heat solution until crystals form
- allow to cool, then filter to obtain crystals
- dry in warm oven
Describe an experiment to prepare a pure, dry sample of a SOLUBLE salt, starting from an acid and alkali
● use a titration to find the exact volume of the alkali that reacts with the acid
● mix the exact volumes of the acid and base
● warm solution so that water evaporates and crystals of the salt remain
Describe an experiment to prepare a pure, dry sample of a soluble salt, starting from an acid and alkali STEP BY STEP
- fill burette with acid
- pipette base into conical flask
- add indicator
- add acid gradually until colour change
- record volume added
- repeat using concordant
- repeat using average volume of acid added and no indicator
- heat solution until crystals form
- allow to cool, then filter to obtain crystals
- dry in warm oven
Describe an experiment to prepare a pure, dry sample
of an INSOLUBLE salt, starting from two soluble reactants
● mix solutions of 2 soluble reactants
● filter mixture (insoluble salt will remain on filter paper)
● wash salt with distilled water
● leave salt to dry in a warm over
all common acids are …. in water
soluble
What is a solvent
The liquid in which a solute dissolves
What is a solute
The substance that dissolves in a liquid to form a solution
What is a solution
The mixture that is formed when a solute has dissolved in a solvent
What is a saturated solution
A chemical solution containing the maximum concentration of a solute dissolved in the solvent
What is solubility
The maximum amount of solute which dissolves in a solvent
