Search results

I've taken a few past papers and divided them by modules, and given them to students of mine to work on if they are struggling to see which parts of modules are struggles, or might need more attention, and also to see which are easier. It makes for might manageable chunks of syllabus to work on...

Yes, you can blame me for that.

It is DrDawn not Drdraw, hence your difficulty in tagging... Don't feel bad, DrDawn, and it hasn't caused conflict. I just saw some irony in @A1La5 commenting on being ninja'd by @yanujw when it was actually @DrDawn who answered first, but that original answer had been removed. On deleting of...

The difficulty of the exams written by organisations to sell to schools have varied over the years. At first, they were being sold and used as complete papers, so they needed to be suited to a broad potential candidature, which meant a similar difficulty level as the HSC. That's one reason...

@jimmysmith560, it's desirable to not be too competitive... after all, your reaction score is more than double mine, from fewer posts, and so one could infer that you are valued at close to triple the rate that I am!

The halogens chlorine and bromine come in pairs of isotopes, a mass of two apart. You can guess what they are from the molar mass: chlorine comes as 35Cl and 37Cl, in roughly 3:1 ratio giving M = 35.5 g mol-1 bromine comes as 79Br and 81Br, in roughly 1:1 ratio giving M = 79.9 g mol-1 These...

@B1andB2 and @username_2, I was asking not call you out, but because I genuinely don't understand. It's one of the problems with written communication, the clues about intent and emotion, etc, conveyed by facial expressions, tone, etc, are missing. I posted an answer to one thread that...

@B1andB2 and @username_2, would you please explain what is humorous about my posts here? Addressing all who have posted here at BoS and readers... I'm quite serious that I don't want to be a cause of participants feeling discouraged from contributing here. My intention is to be helpful, but...

I certainly don't want to be a discouragement to anyone to contribute. :(

I'm not setting out to beat anyone, it's not a competition - I'm just offering some help.

I did indeed complete year 12, including MX2 and chemistry in my studies, but I've done some more study since then, as @idkkdi has noted. :) The first answer took me some time, and the second even longer to work through. Neither is a remotely sensible test of understanding at year 8 level...

You need to notice that the prime factorisation of 2623 is 1 x 43 x 61 Let Z be the lowest common multiple of x and y, which means that Z = ax and Z = by, for some integers a and b. It follows that: \begin{align*} x + y &= \cfrac{Z}{a} + \cfrac{Z}{b} \\ &=\cfrac{Z(a + b)}{ab} \\ \text{And...

I don't know what approach they seek, but my approach (potentially going beyond year 9 or 10 Maths*) is as follows: Rearranging the given equation to make y the subject, I get that y = \cfrac{3x+1}{2x-5} and sketching this gives a rectangular hyperbola with asymptotes at x = \cfrac{5}{2} and...

Question... does the last part of the solution seem strange to anyone else? From the diagram, it appears to me that the maximum height occurs at one second after the ball is thrown.

I've had to delete the post in this thread in which an upload of a copyright-protected NEAP paper was provided. I have also recently had to delete a copy of an HSC paper from the Notes and Resources as NESA-owned materials cannot be hosted by others without their express permission. Please, do...

Calculate delta S = +70 - (131 + 0.5 x 205) = -163.5 J K-1 mol-1 Then, delta G = delta H - T delta S = -286 - 298 x -163.5 / 1000 = -237.3 kJ mol-1 You need to convert the T delta S term into kJ mol-1 before the addition / subtraction to get a meaningful answer.

By the way, B and C would be easily distinguished with their respective IR spectra, giving that one has an O-H bond and the other does not.

Yes, those are also great resources. I was sure you wouldn't be suggesting that anyone do anything wrong. :) BoS can get into trouble if such suggestions are made and they go unaddressed, so I just added the clarification.

Another (similar) way to approach this: \begin{align*} \text{I can travel} \quad &100\ \text{km} \quad \text{using} \quad 10\ \text{L} \quad \text{of fuel} \\ \text{So, I can travel} \quad &\cfrac{100}{100} = 1\ \text{km} \quad \text{using} \quad \cfrac{10}{100}\ \text{L} \quad \text{of fuel}...

Not that anyone here would imply or suggest any sort of copyright violations, so I am sure you mean the PDFs available to those with the codes supplied when purchasing the books. There will likely be cheaper copies of texts available second hand shortly after the HSC is done.