Recent content by walk

thanks - I will keep trying

Sorry - typo- you CAN"T get the cursor to blink into any of the mark boxes

Hi the screen gives 3 colums - Year, Subject and the boxes to put your marks in. You can get the cursor to blink into any of the mark boxes - it will let you submit - then it tell you "warning - you have less than 10 units"....duhhhh!!

Very Frustraing

Yes....should have written that the volume increased by a third to make the concentrations drop like this ...thankx :D

Cl2 went from 0.12 to 0.08 = drop of one third CO went from .06 to .04 = a drop of one third COCl2 went from .03 to .02 = a drop of one third This is because the volume of the container was reduced by one third

It doesnt' matter that citiric acid is weak and doesn't fully ionise - when you do a titration this continually disturbs the equilibrium between the acid molecules and the ions, pulling the equilib to the right every time you add more base - so eventually all three acidic protons are removed...

Acid 1 is strong (check equivalence point pH = 7)) Acid 2 is weak (EP pH = approx 9) Acid 2 needed more KOH for neutralisation so it is more concentrated than Acid 1 You pick an indicator which has an end point colour change as close to the equivalence point pH as possible...

Tin plated steel cans are still used to hold food (as well as polymer coated cans) - so couldn't the questions have also wanted you to talk about the relatively low activity of tin so it doesn't react with most food - but the problem of the tin surface being broken to expose the steel...

Aslo from the Hunter Water site..... "Grahamstown TP Grahamstown water is treated by a conventional filtration process. The plant has a peak supply capacity of 265 megalitres per day and is Hunter Water’s largest water treatment plant. Coagulation is achieved by the addition of alum and...

This comes from the Hunter Water web site.... "Dungog TP The Dungog plant currently provides a peak supply capacity of 90 megalitres per day and treats water from Chichester Dam. Dungog Water Treatment Plant uses a direct filtration method. Alum and polyelectrolyte are rapidly mixed...

2009 HSC 1. C 2. C 3. D 4. C 5. A 6. D 7. B 8. A 9. C 10.B 11.D (don't like question as pH adjustment can also be done to assist with flocculation) 12.A 13.B 14. B 15. A I didn't think that they were too tricky As usual - stupid mutli-step calculations question worth 1 mark...

thanx - yes, did mean aligning.... did u talk 2 any of last yrs yr 12 bout what they thgt they got raw and what they ended up with?

Hi iEdd how do you know about the scaling procedures?

Sorry - I don't understand blog - speak.....anyway - Its 4 am - why aren't you all asleep? - or studying for Chem....