A sample of hydrogen gas was collected over water at 36°C and 855 mmHg. The volume of the container was 6.50 L. Calculate the number of moles of H2 collected. (Vapor pressure of water is 44.6 torr at 36°C)

DrBob really said “I’m going to teach you” I-

I got 0.2733 mol it might be wrong tho so good luck ig

Kanz coming in with the clutch

To calculate the number of moles of hydrogen gas collected, we need to use the ideal gas law equation:

PV = nRT

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

First, let's convert the given pressure and temperature to atm and Kelvin respectively.

Given:
Pressure of hydrogen gas collected = 855 mmHg
Vapor pressure of water = 44.6 torr

To convert mmHg to atm, divide by 760:
855 mmHg / 760 mmHg/atm = 1.125 atm (rounded to three decimal places)

To convert Celsius to Kelvin, add 273.15:
36°C + 273.15 = 309.15 K

Now, we have:
P = 1.125 atm
V = 6.50 L
R = 0.0821 L·atm/(mol·K)
T = 309.15 K

Now we can plug these values into the ideal gas law equation to solve for n:

PV = nRT

(1.125 atm) * (6.50 L) = n * (0.0821 L·atm/(mol·K)) * (309.15 K)

7.3125 = n * 25.388715

Divide both sides of the equation by 25.388715:

n = 7.3125 / 25.388715

n ≈ 0.287 moles

Therefore, the number of moles of hydrogen gas collected is approximately 0.287 moles.

Use PV = nRT

For P: The total P of the system is the pressure of the gas + pressure of water vapor.
Pgas alone = total P - vapor pressure H2O
P gas = 855 - 44.6 = ??
Now convert P in mm to P in atmospheres.
P mm/760 = P atm.
V is in liters.
Don't forget to convert T to Kelvin.
Solve for n.