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the question doesn't ask for molar concentration. and you cant have 0.2 moles of lead since they're is only 0.1 moles to start with

i asked my tutor (he state ranked chem and does chem in uni) and he said that you allow the liquid in the pipette to drain by holding it in contact with the inside wall of the conical flask for about 10secs. So our answer should be correct.

^ but it wouldnt matter if the concentration of the solution in the conical flask changes since the number of moles stays constant. Nevertheless im quite sure that this is wrong.

^ wasn't outline how HCL conc is affected the next part

It listed the steps in which some boy conducted a titration. One of the steps was that he used a pipette to transfer a standard base to the conical flask. He blew on the end of the pipette to ensure that all of the liquid was transferred. Outline a problem in this step and propose a change to...

i did some research and found that air-displacement pipettes (the ones we use in labs) are meant to have some liquid contained in the tip http://en.wikipedia.org/wiki/Air_displacement_pipette http://www.pipette.com/public/staticpages/guidetopipetting.aspx so hopefully we're right

I said just squeeze the ball of the pipette till no more solution can come out since the graduated mark on the pipette accounts for the little bit of solution that remains near the tip of the pipette. So if the guy blew on the pipette, he has transferred extra volume of solution. Some of my...

^ my school was allowed to take options and mcq booklets home. i think most other ppl did too

^ no. Lead is in excess in the reaction, isnt it?

i think he meant 14 or 15

single digits? do you mean the number of marks ive lost in this exam?

lol. thats twice as much as most people would think you'd get

what you get? 12? :p was it just me or did the first 7questions (except2) seem like they could be in the year 8or9 chem comp. Especialy question 4.

i didnt include so much stuff. hopefully i get at least 5 for that. the question really forced ppl to think very 'outside the box' ish. i think its the first time they tested sulfuric as a 7marker in the last 12 years

that looks good as well. the equation vtx gave is probably best though since its more concisse

do you understand what a group in the periodic table is?

^ in your working out if you wrote 0.05 moles i think you might only lose 1 mark.

i talked mainly about Frasch. how this gives a high yield of elemental sulfur but causes many problems such as ground subsidience, soil erosion, thermal pollution (use of superheated water), dust and particulate matter. this has led to a shift in industries to obtain S02 from roasting of metal...

damn should have mentioned LCP. i just said, in acidic solution the Hydronium conc increases, so the equilibrium shifts left to decrease H30+ conc. this increases the concentration of HINd, giving a red colour. Similar thing for basic solutions

i meant that question 5 is A