Recent content by yellowduck

Homework Statement Find Z0 such that P(z > z0) = 0.1234 Homework Equations The Attempt at a Solution Z is the mean which is 0. So if Z0 is less than the mean it should be a negative number. Looking at the table 0.1234 does not show up but the closest is 0.1217 which is 0.31. So Z0...

Ok this seems to help but I still don't quite have it. Lets do a test on say cubic and give an imagingary radius of 1 for each of the 13 units V = (4/3)Pi r^3 = 1.33 x 3.14 x 1 = 4.2 x 13 units = 54.6 units of volume in 13 spheres Sphere volume (radius would be 3) V= (4/3)pi r^3 = 1.33 x 3.14...

Is it possible that I have equation #3 wrong. Should the net ionic equation look like your final answer above?

This should be easy but I feel there is something I am mission I need to write the net ionic equations and then add #1 & #2 and compare to #3. Equation #1 - write net ionic equation for dissolution of solid NaOH in water Equation: NaOH (s) + H2O --> Na+ (aq) + OH- (aq) + H2O (l) Net...

Hi, I am doing a lab on packing methods. Hexagonal closest, face-centred and body-centred. I had no trouble drawing the diagrams for these and and determining cordination numbers and seeing which is more efficient. However I am having trouble explaining the relationship between coordination...

Hi... I am working on this one too and would appreciate it if anyone could take the time to check my answers. By the electrolysis of water, 11.2L oxygen at STP was prepared. a) What charge was required? b) if a current of 0.05A was used, how long did it take? A) the text lists the following...

Thank you, that makes perfect sense now. your help is very much appreciated.

Very, Very Sorry for the double post. Had some computer issues and thought it did not post in this old thread so I stated a new post. Thank you for taking the time to look at this for me... I have updated the answer a bit and if you have time to look at it I would be thankful. 79. Balance the...

Ok, here is another one I have, this is one of a series of half-cell questions... this one is confusing. 79. Balance the following equations by the half-cell method. Show both half-cell reactions and identify them as oxidation or reduction. b) Cl2(g) + OH- <=> Cl- + ClO3^- + H2O(l)...

Ok, I have this question now and the explanation here is not clear to me. this is one of a series of half-cell questions... this one is confusing. 79. Balance the following equations by the half-cell method. Show both half-cell reactions and identify them as oxidation or reduction. b) Cl2(g) +...

Thank you PPonte and Hootenanny for taking the time to review my work and help me out. Thanks Again.

Hmm... yes I seem to mess up on the units sometimes. I would like to do this all in mol/L if possible. (we have been taught to this point only in mol/L) So does this look better? HF + H2O <-> H3O+ + F- HF = 1+19=20 g/mol 2g HF x 1 mol HF / 20g HF = .1 mol HF So HF = .1 mol/L H30+...

My Text mentions nothing about mol.dm^{-3} it does say to calculate [H_3O^{+}] = 10^{-x} So that's how I got .0063 mol/L I also have, from the text the formula for calculating the acid dissociation constant K_{a} Ka = [H30+][X-] / [HX]

Question: A solution of hydrofluoric acid contains 2.0g of HF per litre and has a pH of 2.2. What is the dissociation constant for HF? My Answer: HF + H2O <-> H3O+ + F- HF = 2.0g H30+ = 10^-2.2 = .0063g F- = H3O = .0063 Ka = [H3O+][F-] / HF = (.0063)(.0063) / 2.0 =1.98 x 10^-5...

Thank you Borek for taking the time to check my work.