Answer :

Answer:

n = 0.6 mol

Step-by-step explanation:

I assume this is for the ideal gas law:

PV = nRT

P = 10 atm, V = 2 L, and T = 400 K

You need to choose a R value that has the same units.  In this case:

R = 0.0821 L atm /K /mol

Plugging in and solving for n:

(10 atm) (2 L) = n (0.0821 L atm /K /mol) (400 K)

n = 0.61 mol

Rounding to one significant figure, n = 0.6 mol.