Chemistry
posted by Help please .
I havent been at school for 8 days due to somthing wrong with my heart, but the teachers gave me work. I have no clue how to do them. I really need help please, There all due tomarrow.
Determine the pressure inside a televison picture tube with a volume of 3.5L that contains 2.00 x 105g of nitrogen gas at 22.0C?

Use PV = nRT
T is in Kelvin.
n = moles = grams/molar mass. Solve for P 
okay so what is the R for?

R is a constant = 0.08206 L*atm and give pressure in atmospheres. You can change to torr or mm Hg by multiplying atm x 760.

I cant do it, But thank you for trying to help me,

n = moles N2 = 2.00 x 10^5/28 = ??
The PV = nRT
P*3.5L = ??n*0.08206 x (273+22).
Solve for P in atmospheres.