How many grams of gas are present in a sample that has a molar mass of 70 g/mol and occupies a 2 L container at 117 kPa and 35.1C?
PV = nRT and solve for n = number of mols. Then n*molar msss = grams.
dft7t
To determine the number of grams of gas present in a sample, we need to use the Ideal Gas Law equation:
PV = nRT
where:
P = pressure (in kPa)
V = volume (in L)
n = number of moles
R = gas constant (0.0821 L·atm/mol·K)
T = temperature (in Kelvin)
First, we need to convert the given temperature from Celsius to Kelvin:
T(K) = T(C) + 273.15
T(K) = 35.1 + 273.15 = 308.25 K
Now, rearrange the Ideal Gas Law equation to solve for the number of moles, n:
n = PV / RT
Substitute the given values into the equation:
P = 117 kPa
V = 2 L
R = 0.0821 L·atm/mol·K
T = 308.25 K
n = (117 kPa * 2 L) / (0.0821 L·atm/mol·K * 308.25 K)
Calculate the value of n:
n = 0.924 mol
Finally, multiply the number of moles by the molar mass of the gas to get the mass of the gas:
Mass = n * Molar Mass
Substitute the given molar mass:
Molar Mass = 70 g/mol
Mass = 0.924 mol * 70 g/mol
Calculate the mass of the gas:
Mass = 64.68 g
Therefore, there are 64.68 grams of gas present in the sample.
To determine the number of grams of gas present in a sample, we need to use the Ideal Gas Law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.
First, we need to convert the pressure from kPa to atm (atmospheres) since the ideal gas constant is usually expressed using atm units. 1 atm is equivalent to 101.325 kPa, so 117 kPa is equal to 117/101.325 = 1.155 atm.
Next, we need to convert the temperature from °C to Kelvin (K). To convert from Celsius to Kelvin, we add 273.15. So, the temperature is 35.1 + 273.15 = 308.25 K.
Now, we have all the values we need to solve for the number of moles (n) using the Ideal Gas Law equation. Remember that R is the ideal gas constant, which is 0.0821 L·atm/mol·K.
PV = nRT
n = PV / RT
n = (1.155 atm * 2 L) / (0.0821 L·atm/mol·K * 308.25 K)
n = 0.074 mol
Finally, to calculate the number of grams, we'll use the molar mass of the gas, which is given as 70 g/mol.
Grams = moles * molar mass
Grams = 0.074 mol * 70 g/mol
Grams ≈ 5.18 g
Therefore, there are approximately 5.18 grams of gas present in the sample.