Recent content by needphyshelp

Oops. That was the amount left, not decomposed. Thanks so much for your help! I really appreciate it!

wow. i just recalculate that and have no idea how i got that number. does .577 moles of H2O2 decomposing sound more reasonable? and then .289 O2 formed? using ideal gas law, PV=nRT I have (740)V=.289(62.36)(298.15). V=7.26, but that is not the right answer... im lost.

I think 1.23e-24 moles of H2O2 will decompose, which means 6.14e-25 moles of O2 will be produced, but I still need to find volume. Can I use the ideal gas law to find this?

1/2 mole of oxygen is produced her mole of peroxide decomposed, but I'm not sure I understand how that helps me.

Homework Statement Hydrogen peroxide undergoes a first-order decomposition to water and O2 in aqueous solution. The rate constant at 25°C is 7.40e-4s. Calculate the volume of O2 obtained from the decomposition reaction of 1.00 mol H2O2 at 25°C and 740 mmHg after 12.4 min. Homework Equations...

But how would I calculate the components of the force acting on the pulley? I know nothing about the axle, and it can't be just the tensions on each side because their net force is not zero.

Homework Statement A 12.0kg box resting on a horizontal, frictionless surface is attached to a 5.00 kg weight by a thin, light wire that passes over a frictionless pulley. The pulley has the shape of a uniform solid disk of mass 2.00 kg and diameter 0.500 m. After the system is released, find...

oh... duh.. thanks :-)

Wouldn't that yield pH=log(1.3e-5)+(.030/.1-.030) = 4.52? This answer is incorrect. Is there an initial concentration for C3H5O2- that I am missing?

Homework Statement Calculate the pH after 0.030 mol NaOH is added to 1.00 L 0.100 M HC3H5O2 and 0.100 M NaC3H5O2 Homework Equations Ka=[H+][A-]/[HA] pH=-log([H+]) or 14-pOH=ph The Attempt at a Solution HC3H5O2 <-> H+ + C3H5O2- NaC3H5O2 <-> Na+ + C3H5O2- I know that Na+ has no...

ohhhhhh. that makes sense. thank you so much for your quick reply!

If it is coming from the north, wouldn't it be coming in with a vertical velocity? Or is this just a matter of defining axes?

Homework Statement .100-kg stone rets on a frictionless, horizontal surface. A bullet of mass 6.00g, traveling horizontally at 350 m/s, strikes the stone and rebounds horizontally at right angles to its original direction with a speed of 250 m/s. (a) Compute the magnitude and direction of the...

I still am not getting the correct answer. I don't know what I'm missing. PV=nRT = 1.3E-16(V)=n(.08206)(298) so moles/L = 5.32E-18. I then converted it to moles/cm3 by dividing by 1000, which gave me 5.32E-21 then multiplied by Avogadro's number to get 3203.7 molecules/cm3. I also tried...

I'm sorry - I am trying to convert partial pressure to concentration. Using the Ideal gas equation, PV=nRT, do I use n=2, solve for volume, and then convert to molecules per cm^3?