I said I would give this ago. I by no means got all the questions right, I will check some things in textbooks but I can only guess at some of the answers, please let me know if you disagree with anything that I put.
a) (i) SiO2 + 2C + 2Cl2 > SiCl4 + 2CO a) (ii) Distilled b) (i) SiCl4 + 2H2 > Si 4HCL b) (ii) Reducing agent b) (iii) Explosion as hydrogen gas is flammable c) 2MgO + Si > 2Mg + SiO2
Question 2
a) The forwards reaction is equal to the backwards/reverse reaction Macroscopic properties do not change with time (i.e concentration of substances/colour/pressure)
b) A catalyst lowers the activation energy of a reaction by providing an alternative pathway, therefore it effects the forwards and reverse reaction equally, but has no effect on the position of equilibrium.
c) (i) Increases Equilibrium has been disturbed and will move in a direction to oppose the disturbance. The equilibrium will shift left (to the side with the fewest moles of gas)
(ii) Decreases Equilibrium has been disturbed and will move in a direction to oppose the disturbance. The reaction is exothermic and the position of equilibrium will shift left.
d) (i) A higher temperature increases the rate of the reaction (ii) It is too expensive to maintain a high pressure.
Question 3
a) The fraction of particles with Energy, E b) No effect c) X d) The two different particles must collide and must do so with sufficient energy (Energy greater than or equal to activation energy) e) The particles have more kinetic energy, they move around faster and are more likely to collide and result in a reaction.
Question 4
a) (i) Reduction (ii) Fe3+ +3e- > Fe3 b) (i) The reactants have an enthalpy value of zero (ii) The enthalpy change of a reaction is the same regardless of the route taken from the reactants tot he products (iii) The enthalpy change when one mole of compound is burnt completely in excess oxygen, under standard conditions. With all reactants and products in their standard states. c) +1KJmol-1 d) (i) C(s,graphite) + 2O2 > CO2 (ii) Both form carbon dioxide.
Question 5
a) (i) 0 (ii) +5 b) IO3- + 5I- +6H+ > 3H2O +3I2 iodine? c) (i) I2 (ii) (SO4)2- + 6e- + 8H+ > S + 4H2O d) Hydrogen Sulphide e) (i) I- + Ag+ > AgI (ii) Nothing (iii) To remove ions that would interfere with the test f) (i) An electron donor (ii) Cl2 + 2e- > 2Cl- (iii) Iodide is a larger ion, it's outer shell of electrons is further from the nucleus therefore not as effected by the positive charge of the nucleus. Therefore it loses it's outer electrons more easily, making it a stronger reducing agent.
Question 6 a) Compounds 1 and 3 have the exact same elements, even when measuring to five decimal places their Mr will be exactly the same. The Mr of compounds 1 and 2 to five decimal places would be different as compound one contains an oxygen molecule and compound 2 does not. b) Fehling's Compound 1: Brick red precipitate Compound 2: No reaction or Tollens' Compound 1: Silver mirror forms Compound 2: No reaction
Question 7
a) (i) Increases (ii) Decreases (iii) Increases b) The 'sea' of delocalised electrons gets further away from the nucleus as you go down the group, therefore the metallic bond becomes weaker and the melting points decrease slightly down the group. c) (i) Sulphuric acid contains sulphate ions which would always produce a positive result. (ii) BrCl+ + (SO4)2- > BaSO4 + Cl+
Question 8
a) Positional isomerism b) c)
Question 9
a) C6H12O6 > 2C2H5OH + 2CO2 Fermentation C2H5OH + 3O2 > 2CO2 + 3H2O For a process to be deemed carbon-netural the net production of carbon dioxide must be zero. Fermentation is carbon natural as the the carbon diode released is balanced by that as robed from the plant. The combustion of ethanol is not carbon neutral as carbon dioxide is relaxed in to the atmosphere. b) Nucleophilic Substitution
Potassium hydroxide is used as a reagent and if this contaminates the alcohol and it consumed it would cause ill health. c) Phosphoric acid Hydration High pressure Low temperature
Question 10 a) CADB b) The addition of bromine water, which is a brown/orange colour. When added to a carbon-carbon double it decolourises. Therefore when added to cyclohexane there would be no change and when added to cyclohexene it would decolourise. c) Acidified dicrhomate Oxidation Secondary d) Free-radical substation Initiation: Br-Br > 2Br. Propagation: Br. + CH4 > CH3. + HBr CH3. + HBr > Br. + CH4 Termination: CH3. + HBr. > CH3Br Ultra-violet radiation
Do you by anychance have a webcam, maybe you can take screenshots?
I have a scanner so I'm hoping to scan it and upload it that way *fingers crossed* I figured I would write out the questions, so people can see them if I can't upload the paper.
I have a scanner so I'm hoping to scan it and upload it that way *fingers crossed* I figured I would write out the questions, so people can see them if I can't upload the paper.
I put reduction when I did the exam, but it uses a reducing agent so doesn't that make it oxidation? I'm abit iffy on redox.
but you've gotta remember it's reduction of iron oxide using carbon. yeah carbon is a reducing agent so therefore an electron donor, it gives electrons to iron.
Fe3+ +3e- > Fe3
Iron gains 3e- therefore it has to be a reduction
also will you be posting up the next part? thanks again!
but you've gotta remember it's reduction of iron oxide using carbon. yeah carbon is a reducing agent so therefore an electron donor, it gives electrons to iron.
Fe3+ +3e- > Fe3
Iron gains 3e- therefore it has to be a reduction
also will you be posting up the next part? thanks again!
That does make sense. I will probably do the rest tomorrow now, I had a 2hr Physics exam this morning, I'm feeling pretty exhausted.