Recent content by D.J Falcon

Is this right? If so, I'm ashamed of meself. moles HCl=0.1x0.025=0.0025 Initial concentration CH3NH2=0.0025/0.05=0.05

Homework Statement A known mass of methylamine, CH3NH2, was dissolved in water at 25 celsius 50.0 cm^3 of this solution was taken and titrated with 1.00x10^-1 mol dm^-3 hydrochloric acid solution, HCL(aq). The change in pH as an increasing volume of hydrochloric acid was added is shown in the...

Yeah, I think I managed to do it meself. Forgot it was a strong base. pOH=-log10[OH-] pOH=-log10[0.15M] pOH=0.824 pH+pOH=14 ∴ pH=14-0.824=13.176

Homework Statement A strong base cane be assumed to be fully ionised in dilute solution. Use the Kw value to calculate the hydrogen ion concentration and hence the pH of a 0.15 M solution of potassium hydroxide, KOH.Homework Equations The Attempt at a Solution Problem is, I don't know where to...

I've already made x a constant (T^2/r^3), in the attempt at a solution. I just don't realize what to do from there.

Homework Statement Pluto is 40 times further from the Sun than we are. How long is a year on Pluto? (Use Kepler's third law.) Homework Equations 4∏^2/Gm=T^2/r^3 The Attempt at a Solution Te^2(Earth period)=x*r^3 Tp^2(Pluto period)=x*(40r)^3 I don't know what to do...

Yeah, of course. Perhaps I was thinking of capacitors in series? Anyway, thanks for the help. :smile:

A 40μF capacitor and 20μF are in parallel. With 12V. Calculate total capacitance and V on each capacitor Q=CV E=1/2CV^2 Ct=C1+C2 I don't know where to go from here, calculating total capacitance is easy enough. Don't know how to to calculate V on each capacitor however. Any help would be...

0.36=(K)x(Q1xQ2/0.25^2) Find Q1 and Q2 if Q1=3(Q2) Using the solve function in my calculator I get Q1=2.74x10^-6 and Q2=9.13x10^-7 I would just like to know whether my answer is correct and how to do it in a calculator without using the solve function. Thanks in advance. Edit: Yep sorry...