Chem Final Review

[V|P]

I have a final Tuesday and so I'm reviewing. I'm having problems with a few of these, so I'll post all the ones I have problems with here and help would be appreciated. So far I only have one, but I expect to have a few later.


Molarity:

What volume of 0.166 M NaOH is needed to neutralize 10.0 mL of 0.261 M HNO3?


I'm more interested in how to do this than I am with the answer. The final will probably have a few questions like this, not the exact one.

Here's one I think I got but need to make sure it's right:


Enthalpy

Calculate the enthalpy of reaction for the process:
NO2 + CO yields CO2 + NO
Standard enthalpies:
NO2 = 34 KJ
CO = -111 KJ
CO2 = -394 KJ
NO = 90 KJ


I got 227 KJ for this. Does that seem correct?

[shwaip]

I don't know if you get to assume that they both fully dissociate, but if so, this is how it's done:

M (molarity) has units of moles/liter.

0.261 (moles/liter) * 0.01 (liters) = 0.00261 moles of H+

so you need 0.00261 moles of OH- to neutralize it:

0.166 (moles/liter) * x (liters) = 0.00261
x = 15.7 mL

[V|P]

I don't know if you get to assume that they both fully dissociate, but if so, this is how it's done:

M (molarity) has units of moles/liter.

0.261 (moles/liter) * 0.01 (liters) = 0.00261 moles of H+

so you need 0.00261 moles of OH- to neutralize it:

0.166 (moles/liter) * x (liters) = 0.00261
x = 15.7 mL

The numbers seem right since it is one of the choices, but I'm wondering why you used 0.01 liters in the first step.
NVM I'm stupid, I figured it out after I reread the problem. Just got it mixed up with the enthalpy I just posted.

[shwaip]

how much HNO3 do you have?

[V|P]

Light
What is the energy of a mole of photons of orange wavelength of 585 nanometers.

Since when is this chemistry? I thought this was physics.

l = 3 at a 4f orbital right?

[RWB]

http://www.sparknotes.com/chemistry/

Maybe this will help you out some... I've been reading through it to catch up on my math skills for when I go back to college again.