To determine the missing values, we need to use the ideal gas law equation:

PV = nRT

Where:
P = pressure
V = volume
n = number of moles
R = ideal gas constant (0.0821 L·atm/mol·K)
T = temperature

Given:
n = 1.5 moles
R = 0.0821 L·atm/mol·K

Let's assume the temperature (T) is constant. Therefore, the equation becomes:

P1V1 = n1RT
P2V2 = n2RT

Now we substitute the given values and the unknowns for the second case (N2):

P1V1 = n1RT
P2V2 = 1.5 0.0821 T

Since the number of moles (n) and the temperature (T) are constants, the ratio of pressures and volumes will remain the same:

P1V1 = P2V2
1V1 = 1.5V2
V1 = 1.5 * V2

Therefore, if the number of moles doubles, the volume will be 1.5 times larger.