6. A 2.50 L flask was used to collect a 5.65 g sample of propane gas, C3H8. After the sample was collected, the gas pressure was found to be 956 mmHg. What was the temperature of the propane in the flask?

Assuming the flask was filled with propane only, and propane approximately closely an ideal gas at the given temperature, you can use the ideal gas equation

PV=nRT
where
R=8.314 J-K-1mol-1
P=pressure in pa
V=volume in m³
n=number of mols (pure number)
T=temperature in °K

Hints for conversion
1 m³ = 1000 L
mol = mass / molar mass
1 mmHg = 133.32 pa
°C = °K + 273.15

To find the temperature of the propane gas in the flask, we can use the ideal gas law equation:

PV = nRT

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

First, we need to convert the pressure from mmHg to atm. Since 1 atm = 760 mmHg, we can use the conversion factor:

Pressure (in atm) = Pressure (in mmHg) / 760

So, the pressure in atm becomes:
Pressure (in atm) = 956 mmHg / 760 mmHg = 1.257 atm (rounded to 4 decimal places)

Next, we can rearrange the ideal gas law equation to solve for temperature:
T = PV / nR

We have the pressure (P) as 1.257 atm and the volume (V) as 2.50 L. However, we still need to find the number of moles (n) to calculate the temperature.

To find the number of moles, we can use the molar mass of propane (C3H8). The molar mass is calculated by summing the atomic masses of all the elements in the chemical formula.

C = 12.01 g/mol (carbon)
H = 1.008 g/mol (hydrogen)

For propane (C3H8), the molar mass is:
(3 * 12.01 g/mol) + (8 * 1.008 g/mol) = 44.11 g/mol

Now we can calculate the number of moles:
n = mass / molar mass
n = 5.65 g / 44.11 g/mol

n ≈ 0.1282 moles (rounded to 4 decimal places)

Finally, we substitute the known values into the rearranged ideal gas law equation to find the temperature:
T = (1.257 atm * 2.50 L) / (0.1282 mol * 0.0821 L.atm/mol.K)

By performing the calculation, we find the temperature of the propane gas in the flask.