Question

How many grams of nitrogen are in a flask with a volume of 250 mL at a pressure of 1500mm of Hg and a temperature of 27 C?

Answer 1

Some how I got 426515.6, but i am almost definite that this is incorrect.

Answer 2

did you use the three gas laws

Answer 3

I plugged in 1500(250)=n(.08206)(300)
And then I tried to convert the moles into grams

Answer 4

we have three gas laws, where we assume ideal gases
1. PV = k (temperature held constant)
2. V/T = k (pressure held constant)
3. P/T= k (volume held constant)
The combined gas law is PV = kT
Avagadro's gas law is PV = nRT
http://chemistry.bd.psu.edu/jircitano/gases.html

Answer 5

so lets use avagadros gas law, we need to use kelvin , k = 273.15 + C

Answer 6

to use avagadro's gas law, R = .08206, V is in liters, P is in atm's and T is in kelvins , n = gas molar mass

Answer 7

and nitrogen is diatomic , dont forget

Answer 8

first convert 1500mm of Hg into atm

Answer 9

google says
1500 mm Hg =1.97368421 atm

Answer 10

PV = nRT
(1.97368421 atm)(.250 L) = n * .08206 * (27 + 273.15 Kelvins)

Answer 11

solve for n, that gives you number of moles of N2

Answer 12

PV = nRT
(1.97368421 atm)(.250 L) = n * (.08206 L-atm / mol-K) * (27 + 273.15 K)
notice that the units cancel
n = (1.97368421 * .250 / (.08206 * 300.15) moles of N2

Answer 13

n = .02 moles roughly
now N2 is 28 grams / mole

Answer 14

(.02 moles of N2 ) *( 28 g N2 ) / ( mole of N2) = 0.56 grams of N2

Answer 15

is that correct?

Answer 16

also you can use wolfram to find the answer
http://www.wolframalpha.com/input/?i=mass+of+nitrogen+gas+250+mL+at+1500mm+of+Hg+at+temperature+of+27+Celsius