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re: HSC Chemistry Marathon Archive Yes it is A

re: HSC Chemistry Marathon Archive Which of the following will cause the greatest change in pH to a 100mL sample of 0.1 molL-1 HCL? A. adding 1g of CaCO3 powder B. adding 10mL of 0.1 molL-1 NaOH C. adding 100mL of 0.1 molL-1 HCL D. diluting the sample to 1000mL Please show your working if...

re: HSC Chemistry Marathon Archive A student wanted to determine the phosphate content in a certain brand of washing detergent. The phosphorus was precipitated as Ca2P2)7 and then filtered. A 4.42g sample of washing detergent resulted in a precipitate of mass 0.232g. Calculate the percentage of...

re: HSC Chemistry Marathon Archive Thanks! That will do!

re: HSC Chemistry Marathon Archive Can you show me your working? Cause I still dont really understand.....

re: HSC Chemistry Marathon Archive Actually, it's per 100 but I know it's a typo :p Yea it is. But tell me how you get it, otherwise it"s pointless

re: HSC Chemistry Marathon Archive The pH of a 0.1 mol L-1 solution of a monoprotic acid was measured by a student and found to be close to 3. What proportion of the acid molecules remains unconverted to ions?

Yeah its A. Reason? Because I don't think the collecting ducts can increase in length(not really sure)

Are the ones in Usyd good?

How does a plant respond in order to keep cool on an extremely hot day? A. It grows smaller leaves. B. It opens stomata in the leaves. C. It grows more hairs on the surface of the leaves. D. It decreases the number of stomata on the top of the leaves.

Which of the following results in an increased absorption of water from the collecting tubule of the nephron? A. An increase in the length of the collecting tubule B. A decrease in ADH released into the blood by the pituitary C. A decrease in glucose moving from the renal tubule into...

re: HSC Physics Marathon Archive Sorry! its 40. But still, what does 45 degrees have to do with this? The book says its maximum but I dont understand what it means by that

re: HSC Physics Marathon Archive Yeah but wouldnt A work as well? Seeing as the angle was increased, thus the shot can travel further before hitting the ground?

re: HSC Physics Marathon Archive HSC 05 Q5: Napoleon attacked Moscow in 1812 with his cannon firing a shot at an elevation angle of 45 degrees. Napoleon then decided to fire a second shot at the same speed but at an elevation angle of 50 degrees. Which of the following observations would...

re: HSC Chemistry Marathon Archive With this are we not just calculating the concentration of just Copper? Edit: Nvm I got it. Thanks!

re: HSC Chemistry Marathon Archive A beaker initially contained 250ml of 0.05mol per litre copper sulphate solution. A piece of zinc metal is put into it and after a while, 0.325g of copper was deposited. Calculate the concentration of copper sulphate remaining in the beaker.

Ok I finally get it.

Can you explain the other one, 4/x?

But the answer is 4lnx + c. Also, what about 3x/(x^2+7)?

How about 4/x? How do you integrate that?