1.09 g of H2 is contained in a 2.00 L container at 20.0 °C. What is the pressure in this container in atm?

To solve this problem, we can use the ideal gas law equation:

PV = nRT

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

First, let's convert the given temperature from Celsius to Kelvin:
T(K) = 20.0 + 273 = 293 K

Next, we need to calculate the number of moles of H2:
Given mass of H2 = 1.09 g
Molar mass of H2 = 2 g/mol
Number of moles = 1.09 g / 2 g/mol = 0.545 mol

Now, plug in the values into the ideal gas law equation:
P(2.00) = (0.545)(0.0821)(293)
P(2.00) = 13.66

Therefore, the pressure in the container is 13.66 atm.