Problem: An unknown gas contained in a 1.85 L flask is weighed and found to have a mass of 15.87 g at a pressure of 2.45 atm and a temperature of 18.6°C. What is the molecular weight of the gas?a. 5.35 g/molb. 83.8 g/molc. 1.14 g/mold. 155 g/mole. 77.1 g/mol

🤓 Based on our data, we think this question is relevant for Professor Bindell's class at UCF.

FREE Expert Solution

We’re being asked to determine the molecular weight of the unknown gas.

Recall that molecular weight is in grams per 1 mole of a substance.

First, we have to calculate the amount of gas in moles using the ideal gas equation.

$\overline{){\mathbf{P}}{\mathbf{V}}{\mathbf{=}}{\mathbf{n}}{\mathbf{R}}{\mathbf{T}}}$

P = pressure, atm
V = volume, L
n = moles, mol
R = gas constant = 0.08206 (L·atm)/(mol·K)
T = temperature, K

Isolate n (number of moles of gas):

Problem Details

An unknown gas contained in a 1.85 L flask is weighed and found to have a mass of 15.87 g at a pressure of 2.45 atm and a temperature of 18.6°C. What is the molecular weight of the gas?

a. 5.35 g/mol

b. 83.8 g/mol

c. 1.14 g/mol

d. 155 g/mol

e. 77.1 g/mol

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Ideal Gas Law Molar Mass concept. If you need more Ideal Gas Law Molar Mass practice, you can also practice Ideal Gas Law Molar Mass practice problems.

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What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Bindell's class at UCF.