1. Calculations Formula mass MgO C3H7OH Ca(OH)2 CH3COOC4H9 24 + 16 =40
3x12 + 7x
=60
40 + 2x(16 + 1)
=74
12 + 3x x16 + 4x12 + 9x1
= 116

2. Equations and formula mass
CH3COOH + C2H5OH  CH3COOC2H5 + H2O
What mass of ethyl ethanoate can be made from
0.23 g of ethanol?
Calculate formula masses of the compounds in the question
C2H5OH = 2x12 + 5x1 + 1x16 + 1x1
= 46
CH3COOC2H5 = x x16 + 2x12 + 5x1
= 88

3. Equations and formula mass
CH3COOH + C2H5OH  CH3COOC2H5 + H2O
What mass of ethyl ethanoate can be made from
0.23 g of ethanol?
Calculate mass of unknown chemical from 1g known chemical
46g ethanol gives 88g ethyl ethanoate
1g ethanol gives 88/46g ethyl ethanoate
Calculate mass of unknown from given mass
0.23g ethanol gives 0.23x88/46
= 0.44g

4. Equations and formula mass
H3PO4 + 3 KOH  K3PO4 + 3 H2O
What mass of potassium phosphate can be made from 0.56 g of potassium hydroxide?
Calculate formula masses of the compounds in the question
KOH = 1x39 + 1x16 + 1x1
= 56
K3PO4 = 3 x x31 + 4x16
= 212

5. Equations and formula mass
H3PO4 + 3 KOH  K3PO4 + 3 H2O
What mass of potassium phosphate can be made from 0.56 g of potassium hydroxide?
Calculate mass of unknown chemical from 1 g known chemical
3 x 56 = 168 g potassium hydroxide gives 212 g potassium phosphate
1g potassium hydroxide gives 212/168 g potassium phosphate
Calculate mass of unknown from given mass
0.56 g potassium hydroxide gives 0.56 x 212/168
= 0.71g

6. Concentration (g/dm3) = mass (g)/volume (dm3)
1 dm3 = 1000 cm3
1 cm3 = 1/1000 dm3
Calculate the concentration in g/dm3
0.25 g Na2CO3 in 100 cm3
15.0 g HCOOH in 500 cm3
0.25/0.1
= 2.5 g/dm3
15.0/0.5
= 30.0 g/dm3

7. mass (g) = concentration (g/dm3) x volume (dm3)
1 dm3 = 1000 cm3
1 cm3 = 1/1000 dm3
Calculate the mass of solute dissolved in
25.0 cm3 4.0 g/dm3 CH3COOH
27.3 cm g/dm3 H2SO4
4.0 x 25.0/1000
= 0.10 g
10.0 x 27.3/1000
= g

8. Equations and formula mass
HCl + NaOH  NaCl + H2O
25.0 cm3 0f g/dm3 HCl is added to a conical flask using a __________. A few drops of phenolphthalein (an indicator) is added. NaOH is added from a ________ until the indicator produces a permanent pink colour. The process is repeated until two values within 0.20 cm3 are obtained – why is this necessary? The mean value was found to be 27.5 cm3 what is the concentration of the sodium hydroxide?
Calculate formula masses of the compounds in the question
NaOH = 1x23 + 1x16 + 1x1
= 40
HCl = 1x1 + 1x35.5
= 36.5

9. Equations and formula mass
HCl + NaOH  NaCl + H2O
25.0 cm3 0f g/dm3 HCl. NaOH is added. The mean value was found to be 27.5 cm3 what is the concentration of the sodium hydroxide?
Calculate mass of the substance we have the concentration (g/dm3) and volume (cm3) for
Mass HCl = conc x vol = x 25.0/1000 = g
Calculate the mass of unknown from 1 g of the known species
36.5 g HCl reacts with 40.0 g NaOH
1 g HCl reacts with 40.0/36.5 g NaOH
= g
Calculate the mass of unknown required
x 1.096
= g NaOH
Calculate the concentration
Conc (g/dm3) = mass (g)/vol (dm3)
= 0.01/(27.5/1000)
= g/dm3

10. Some key areas to revise
Green chemistry: yield (equilibrium); feedstock sustainability; atom economy; by products; catalysts
Bond energies: breaking bonds is endothermic (requires energy); making bonds is exothermic (releases energy to surroundings); Total energy (of system) = bonds broken - bonds made; negative = exothermic; positive = endothermic; energy level diagrams
Reversible reactions and equilibrium: ⇌; dynamic equilibrium when rate forward = rate backwards
Catalysts: speed up rate of reaction by providing alternative route with lower activation energy; catalyst is not used up

11. Some key areas to revise
Acids
Strong acids: fully ionise (dissociate) HCl (aq)  H+ (aq) + Cl- (aq)
Weak acids: partially ionise (dissociate) CH3COOH (aq) ⇌ CH3COO- (aq) + H+ (aq)
Reactions:
CH3COOH + LiOH  CH3COOLi + H2O
2 HCOOH + Mg  (HCOO)2Mg + H2
2 C2H5COOH + CaCO3  (C2H5COO)2Ca + CO2 + H2O
HCOOH + CH3OH  HCOOCH3 + H2O

12. Some key areas to revise
Chromatography:
Stationary phase
Mobile phase (a solvent)
Sample is in dynamic equilibrium between the phases
More soluble samples travel further
Rf = distance moved by sample/distance moved by solvent
Paper chromatography: paper and water
Thin layer chromatography (TLC): silica sprayed onto e.g glass and e.g. ethyl ethanoate
Gas chromatography: liquid on beads and inert gas e.g. argon

13. Some key areas to revise
Synthesis of ester
Heat alcohol and carboxylic acid with acid catalyst under reflux: heat speeds up reaction; vertical condenser prevents reactants/products escaping
Fractional distillation: condenser pointing down
Removal of acidic impurities: tap funnel; mix product with aqueous sodium carbonate; impurities dissolve in aqueous layer which is tapped off
Dry with anhydrous calcium chloride
Fractional distillation

14. Some key areas to revise
Organic chemistry
Alkanes: CnH2n+2 e.g. methane CH4; unreactive because of strong C-C & C-H bonds; immiscible in water; burn to produce CO2 and H2O
Alcohols: -OH e.g. ethanol C2H5OH; burn to produce CO2 and H2O; 2 CH3OH + 2 Na  2 CH3ONa + H2
Carboxylic acids: -COOH e.g. propanoic acid C2H5COOH; weak acid
Ester: alcohol + carboxylic acid e.g. butyl butanoate C3H7COOC4H9
Fats/oils: esters of long chain carboxylic acids and glycerol; oils – unsaturated (contain >C=C<); kink causes lower melting point; fats – saturated; chains line up

15. Some key areas to revise
Ethanol manufacture
Fermentation of sugars: C6H12O6  2 C2H5OH + 2 CO2; feedstock renewable but it requires agrichemicals, water and land; 37oC and yeast; max 15-20%; needs to be distilled
Genetically engineered organisms can produce ethanol from waste carbohydrate – reduces food issues
Hydration of ethene: C2H4 + H2O  C2H5OH; crude oil feedstock is finite; 300oC and H3PO4 catalyst

16. Some key areas to revise
Life cycle assessment
Manufacture: feedstock (sustainable? Effect on landscape/environment?); energy - electrolysis; transport; pollution
Use: pollution while driving; electricity generation
Disposal: toxicity; reuse; recycle; landfill;
reduce; reuse; recycle
Making decisions
What other factors might influence people’s decisions?
Reactions of group 1
React with: water to form hydroxides (MOH) and hydrogen (H2); oxygen to form oxides (M2O)
Reactivity increases down group
React to form M+ ion by losing an electron: more electron shells reduce the attraction from nucleus