Recent content by Ryaners

Ah, yes, that does make a quite a bit of a difference alright, whoops :redface: Thank you for pointing out the mistake! Fresh pair of eyes etc.

Homework Statement I've completed an experiment where the dependence of magnetic field strength ##B## on current ##I## is measured at the midpoint along the axis between two Helmholtz coils (separation distance = coil radius ##r##). I got the expected linear relationship from the data but am...

I'm having a difficult time understanding why the internal resistance of the EMF source is disregarded in this problem. 1. Homework Statement You are asked to determine the resistance per meter of a long piece of wire. You have a battery, a voltmeter, and an ammeter. You put the leads from the...

Yes! That's it, thank you so much! You wouldn't believe how long I spent tearing my hair out over this yesterday. Learning is hard. :redface: I'm a bit confused about something I think. I've learned that the rate of formation of product = - rate of consumption of reactant (which makes sense)...

I'm trying to solve one of the problems in my textbook (Atkins Physical Chemistry) and I just can't get it out. Here's the problem: "The data below apply to the formation of urea from ammonium cyanate. Initially 22.9g of ammonium cyanate was dissolved in enough water to prepare 1.00 dm3 of...

That's a fair point - though I get the same result: $$ \left( M_{sun} \right) ^\frac {1}{3} R_{sun} = \left( M_{D} \right) ^{\frac {1}{3}} R_D $$ $$ \Rightarrow R_D = \left( \frac {M_{sun}} {M_D} \right) ^{\frac{1}{3}} R_{sun} $$ $$ \Rightarrow R_D = \left( \frac {1}{1.3} \right) ^{\frac...

Homework Statement Calculate the radius of a 1.3 Msun white dwarf using the mass-radius relation for white dwarfs. Give the answer in solar radius. Homework Equations Mass-radius relation: $$R \propto M^{-\frac{1}{3}}$$ The Attempt at a Solution So I've tried the following: $$R_{D} \propto...

Ok, so basically I'm scuppered by the low yield - that's what I suspected. Thanks for your input @Borek & @BvU , was good to think through the problem regardless :)

Thanks for the response! So there are 2 moles C5H8O2 per mole of VOSO4.xH2O, which tells me that The Na2CO3 is in excess & won't affect yield If the stoichiometric amount of VOSO4.xH2O was used, that would be (0.5 x 0.0242 mol) = 0.0121 mol of VOSO4.xH2O. This is closest to x=2 in the formula...

Homework Statement [/B] I had an inorganic lab this week which involved making VO(acac)2 from VOSO4⋅xH2O. In order to calculate the percentage yield, I need to work out x, that is, the number of water molecules coordinated with the vanadyl sulfate n-hydrate before the reaction. I'm stuck...

So by multiplying the formula by ##r## in order to start the index at 1 instead of 0, it becomes ## \sum_{n=1}^{\infty} \frac {ar} {1-r} ## where ##a = a_0 = 1## for both series (because when summing a geometric series from ##n=1##, the first term is ##a_1 = ar##). The sum of each series is...

Ah ok, my mistake. Thank you all for pointing that out, I didn't realize the formula would change if the index changed, though of course that makes sense. Cheers!

Homework Statement Find the sum of the following series: $$ \left( \frac 1 2 + \frac 1 4 \right) + \left( \frac 1 {2^2} + \frac 1 {4^2} \right) +~...~+ \left( \frac 1 {2^k} + \frac 1 {4^k} \right) +~...$$ Homework Equations $$ \sum_{n = 1}^{\infty} \left( u_k+v_k \right) = \sum_{n =...

I get it now, thanks for your input :)

Yes! Ok! This is making sense now. So the safest thing to do is to put the quadratic in a form where the coefficient of the x2 term is 1 before applying the quadratic formula, so you don't lose track of any constant factors while finding the roots. That's exactly the insight I was looking for...