I don't know exactly how to start this question:
A sample gas contains 2.95 x 10e24 molecules. The sample is 21.0% oxygen. Calculate volume of oxygen in liters assuming oxygen has a density of 1.308 g/L.
Please help me how to do this. I have been stuck and still trying to figure this one out.
figure moles of gas first; moles=2.95E24/avag number
then moles O2=molestotal*.21
then mass 02=molesO2*32grams/mole
then volume=massO2/density
Okay. Please check. If you can please show me how its done when you put it together. I have it scattered so I was a bit stuck when I tried to do each step. I know dimensional analysis allows the cross cancelling when you do it on paper and its hard to see whats cancelled in each step on the computer. Thank you so much.
2.95E24/6.02E23=4.90 mol (g)
(4.90mol O)(0.21 O)=1.029 mol O
2(15.9994)=31.9988 g/mol O:
(1.029 mol O)(31.9988 g/mol)=32.9267652g
31.9988g/1.308L=24.46 L
Why don't you put it together on paper so you can see what cancels?
To solve this problem, you will need to use the given information and the concepts of moles, molar mass, and the ideal gas law.
Here's the step-by-step explanation:
Step 1: Calculate the number of oxygen molecules in the sample.
The given information states that the sample contains 2.95 x 10^24 molecules. Since the sample is 21.0% oxygen, the number of oxygen molecules can be calculated by multiplying the total number of molecules by the percentage of oxygen:
Number of oxygen molecules = (2.95 x 10^24) x (0.21)
Step 2: Convert the number of oxygen molecules to moles.
To convert the number of oxygen molecules to moles, you'll need to use Avogadro's number, which is approximately 6.022 x 10^23 molecules/mol:
Number of moles of oxygen = (Number of oxygen molecules) / (Avogadro's number)
Step 3: Calculate the mass of the oxygen using the molar mass.
The molar mass of oxygen is approximately 32 g/mol. Multiply the number of moles of oxygen by the molar mass to obtain the mass:
Mass of oxygen = (Number of moles of oxygen) x (molar mass of oxygen)
Step 4: Calculate the volume of oxygen using the density.
The given density of oxygen is 1.308 g/L. Divide the mass of oxygen by the density to obtain the volume in liters:
Volume of oxygen = (Mass of oxygen) / (Density of oxygen)
By following these steps, you should be able to calculate the volume of oxygen in liters.