Recent content by hobomoe

I got the top one right I'm pretty sure. The bottom one is regarding precipitates, so Qs can't be greater than Ks. I got that the scientist was right but I'm too lazy to type it out.

I had these two questions in a test and I was completely stumped. 1. Make a 1-2L buffer solution containing methanoic acid and methanoate ions and with a pH of 3.74 using 1.07molL-1 HCOOH, solid HCOONa, 1.04molL-1 HCl, 1.16molL-1 NaOH(not all together). pKa(HCOOH)=3.74 M(HCOONa)=68gmol-1...

Acidified potassium dichromate, so its acidic. Don't need to go super indepth, it's only final high school year redox.

zzz so many views and no answer

Homework Statement Acidified potassium dichromate is an oxidant. It will react with titanium metal which is oxidised to form titanium ions. Show that Ti^3+ and not Ti^2+ is formed in the reaction. Your answer should include chemical equations for any possible reactions and justification for...

I've read in places that you just times the uncertainty by two when you square x and divide it by 2 when you square root it :S

(High-school level) I got given some formulas today for calculating uncertainty of a value that has been square rooted, squared, inversed, inverse squared and inverse square rooted. I'm not totally sure what they mean however, but I kinda have an idea. Square root: y=x^1/2...

Oh haha big derp by me.. THANK YOU! Been stressing me out..

The answers are opposites of each other so where did I go wrong in one of the equations? (ones positive and ones negative)

I did do that to get 2cotA(cosA-cosecA)(tan^2 A) = 2(sinA-secA). One tanA cancels out cotA and the other changes the cosA and cosecA. Or am I wrong?

They do equal. We're only asked to prove that they do, not to find out if they do or not.

Better?

Homework Statement Prove that (1-sinA)/(1-secA) - (1+sinA)/(1+secA) = 2cotA(cosA-cosecA)Homework Equations tan^2+1=sec^2The Attempt at a Solution Times (1-sinA)/(1-secA) - (1+sinA)/(1-secA) = 2cotA(cosA-cosecA) by (1-sec^2 A) to get (1-sinA)(1+secA) - (1+sinA)(1-secA) =...

I'm lost.. I don't know how to work any of this out..

Homework Statement The distance of point X (k,2) from the line y=x+4 is four. Find the values of k. Homework Equations The Attempt at a Solution (y-2)/(x-k)=-1 y=-x+k+2 I think this gives me the equation of the line from the point to the line y=x+4, but not sure what to do next...