test Flashcards
% Atom Economy
(Mr of desired product/Mr of all products) x 100
% Yield
(Actual Yield/Theoretical Yield) x 100
% Yield Steps
Moles of the the reactant
Molar Ratio
Theoretical mass
: t.m = moles x Mr
% yield - (A.Y/T.Y) x 100
% Purity
% purity: (actual mass/impure mass) x 100
Working out % purity
1) moles of the pure substance
2) molar ratio for pure : impure
3) actual mass : moles x Mr
4) %purity : (actual mass/impure mass) x 100
Anhydrous
Contains no molecules of water of crystallisation
Hydrated
Contains molecules of water of crystallisation
Acid Definition
Released H+ ions in an aqueous solution
Strong Acid definition
Acids that completely disassociate (break into ions) when dissolved in water
Weak Acid Definition
Only slight disassociates when dissolved in water, giving an equilibrium mixture
Base Definition
A substance which neutralises acids
Proton ( H+) doner
Alkali Definition
A soluble base that releases OH- ions in aqueous solutions
Salt definition
The hydrogen of the acid is replaced by a metal or other cation
Acid + Base —> Salt
Salt full definition
A chemical compound formed from the reaction of an acid and a base where all or part of the hydrogen of the acid is replaced by a metal or other cation
Neutralisation 1
Acid + Base —> Salt + Water
Neutralisation 2
Acid + Alkali —> Salt + Water
Neutralisation 3
Acid + Carbonate —> Salt + CO2 + H2O
Neutralisation 4
Acid + Ammonia —> Ammonium Salt
Observations
MgO —> Always a white solid
(g) —> Effervescence/ Fizzing
nothing —> solid
Ionic Equations Rules
1) Metals are solid (s)
2) Salts in solution are aqueous (aq)
3) Ions are aqueous (aq)
4) Acids/Alkalis are aqueous (aq)
5) H2O is a liquid (l)
Ionic Equation steps
Put the state symbols e.g (aq)
Separate the aqueous substances into ions
Cancel the ions that appear on both sides
Write the ionic equation
Ionic Bond Definition
Strong electrostatic forces of attraction between oppositely charged ions
Electrical Conductivity of Ionic compounds
Solid state —> Will NOT conduct electricity as ions are in a. fixed lattice position
Molten/Aqueous —> Will conduct electricity because they have mobile charged carriers
Covalent bond Definition
A covalent bond is a shared pair of electrons between atoms
Co-ordinate bonding/Dative Covalent Bonding
When one atom provides both the electrons needed to form a covalent bond
Polyatomic ions
Ammonium- NH4(+)
Hydroxide- OH(-)
Nitrate (v) NO3(-)
Carbonate - CO3(2-)
Sulfate (VI) - SO4(2-)
Phosphate - PO4(3-)
Uncertainties
% error = margin of error
——————— X 100
quantity measure
