Answer:
5.0mol
Step-by-step explanation:
Use the ideal gas law, PV = nRT
P = 12atm, V = 10L, R = 0.0821 atm•L/mol•K, and T = 20°C
First, convert the temperature to kelvin by adding 273.15. That's 293.15.
Now, modify the equation to solve for mols. That's n = PV/RT.
Input your values:
n = (12atm)(10L)/( 0.0821 atm•L/mol•K)(293.15K)
n = 4.985953116mol
Round to 2 significant figures to get 5.0mol
(I don't know if you usually do rounding so you may want to keep the answer exact)