Question

Calculate the volume that 12.5 g of Co, gas will occupy at a
temperature of 40°C and a pressure of 1.20 atm.

Answer 1

m = 12.5 g
T = 40 C = 313 K
P = 1.20 atm
R = 0.0821 L.atm/mol.K (constant)
V = ??

Using equation
PV = nRT

Find the number of moles which is
n = m/Mr
Mr (find it in the periodic table)

So, then apply the values
V = nRT / P
and you will got the volume

Actually I didn't solve it, because I didn't understand the substance, is it Co (Cobalt) or CO (carbon monoxide)??

If it Co, so the number of moles will be
n = 12.5 g / 59 g/mol
:. n = 0.212 g/mol

So the volume is
V = (0.212 g/mol x 0.0821 L.atm/mol.K x 313 K) / 1.20 atm

:. V = 4.54 L