Follow up on a chemistry Morality question, I need a walk through please?

C

Capacino

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Solid copper reacted with nitric acid in 5.00 liters of water. Copper nitrate and nitrogen monoxide are formed. If the volume of nitrogen monoxide collected over water was 1.50L at 25C and 1.00atm, how much copper must have been reacted?

This was my homework:

PV = nRT

Assuming NO(g) behaves like an ideal gas,
the moles of gas collected is:

n = moles = PV/RT

P = .969atm
V = 1.50L
R = 0.08206 atm*L/mol*K
T = 25ºC + 273.15 = 298.15 K

n = [.969 atm x 1.50L]/[0.08206 (atm*L/mol*K) x 298.15 K]

n = 0..0594mol NO(g)

From the balanced equation,
3Cu(s) + 8HNO3(aq) → 3Cu(NO3)2(aq) + 2NO(g) + 4H2O(l)

==> 3 mol Cu = 2 mol NO

MW Cu = 63.546 g/mol

g Cu =
(0.613091 mol NO)
x (3 mol Cu / 2 mol NO)
x (63.546 g Cu / 1mol Cu)
= 5.66 g Cu

The Follow up Question:

Assuming the nitric acid was present in Stoichiometric amount for problem 2 what is the morality of the nitric acid?

This part is confusing me b/c to get the M of a nitric acid I would need to use M=n/v. I can get n which would be .9197*8/3=2.45 but then how would I get the volume? I know the volume of the reactants combined is equal to 5L but how do I isolate the 8HNO3? or am I thinking about this the wrong way?
 
nitric acid has no morality. it is truly evil. 100%. You make explosives from it. lol!
as far as molarity goes, thats a different question.
You lost me on the 0.9197 - - wtf did that come from?
you say that NO is present at n = 0.0594
the stoichiometry is 8HNO₃ → 2 NO 8:2 or 4:1 well 4x 0.06 is not 2.45
it is about 0.2376 moles in 5L or 0.0475M
This ignores the volume of the HNO₃
A google search indicated a sp gr of 1.52 g/cc so .2376 moles is 15g or 10 ml - - so 0.2376/5.010 = 0.0474M
note two things actually three
1) NO will have a solubility in water and so all will not be collected
2) ideal gas law is good to within 1 - 10% depending on gas, using an estimate of 5%, you do not get 3 decimal accuracy!
3) obviously there will NOT be a stoichiometrically exact elimination of the acid - some will not react.
My point is that 0.047M is a better answer IMHO that 0.0474M
molality is moles per liter of water. molarity is moles per liter
(the 1.522 sp.gr. was at low temp, so approximate)
It is generally not useful to think about total molarity in a solutin of diverse components. Just calculate moles of specific material of interest per liter. {5 g of Cu will be < 1 ml so I'm ignroing it} Accounting for the solutes volumes at high dilution is generally accepted to be unnecessary (but is easy enuff to approximate as I showed).
 
I think you must take the total volume of the solution to be 5L, as there is no other information to be found in the question.
You can therefore use the formula that you stated to find the molarity of the nitric acid.
 
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