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Determine the molar mass of a gas if the volume of 0.05 g of the gas is 50cc at 27°c and 76 cm Hg pressure.

User Scuttle
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1 Answer

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

PV = nRT

where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is the temperature in Kelvin.

First, we need to convert the volume to liters and the temperature to Kelvin:

V = 50 cc = 0.05 L
T = 27 + 273 = 300 K

Next, we can rearrange the ideal gas law to solve for the number of moles:

n = PV/RT

where P is pressure in atm, V is volume in liters, R is the gas constant in L·atm/mol·K, and T is temperature in Kelvin.

We need to convert the pressure from cm Hg to atm:

P = 76 cm Hg × 1 atm/76 cm Hg = 1 atm

Plugging in the values:

n = (1 atm) × (0.05 L) / [(0.0821 L·atm/mol·K) × (300 K)]
n = 0.0021 mol

Finally, we can calculate the molar mass using the mass and the number of moles:

molar mass = mass / moles

molar mass = 0.05 g / 0.0021 mol

molar mass = 23.81 g/mol

Therefore, the molar mass of the gas is 23.81 g/mol.