chemistry help again. help please?

Question

using the ideal gas law.
if you are given
molar mass- 77.95g/mol
density- 6.27 g/L
temperature- 66°C
and you need to find pressure, how would you go about doing that
thanks

Answer 1

PV=nRT
n=m/M m is mass, M is molar mass
replace n=m/M
PV=(m/M)*RT
P=(m/M)*RT/V
P=(m/V)*RT/M
P=d*RT/M cuz density=m/V m is mass, V is volume
M=77.95, d=6.27, T=273.15+66= 339.15K, R=.08206
P=6.27*.08206*339.15/77.95= 2.24 atm
that is answer but when you put the number in i recommend you write down the units like P=6.27g/L ect.... so instructor can see what is going on. cuz i am lazy to write down lol
good luck

Answer 2

PV = nRT
P = nRT/V = RT n/V
You're given n/V = density/molar mass
T needs to be converted into K = C + 273.15