Convert moles to mass.
mass C = 0.2 mol * 12 g / mol = 2.4 g
mass H = 0.4 mol * 1 g / mol = 0.4 g
So mass left for O = 6 g – (2.4 g + 0.4 g) = 3.2 g
Calculating for moles O given mass:
moles O = 3.2 g / (16 g / mol) = 0.2 moles
Answer:
0.2 moles O
Answer : The moles of oxygen present in the sample is, 0.2 moles
Explanation : Given,
Moles of carbon = 0.200 mole
Moles of hydrogen = 0.400 mole
Mass of unknown compound = 6.00 g
Molar mass of carbon = 12 g/mole
Molar mass of hydrogen = 1 g/mole
Molar mass of oxygen = 16 g/mole
First we have to calculate the mass of carbon and hydrogen.
[tex]\text{Mass of carbon}=\text{Moles of carbon}\times \text{Molar mass of carbon}=(0.200mole)\times (12g/mole)=2.4g[/tex]
[tex]\text{Mass of hydrogen}=\text{Moles of hydrogen}\times \text{Molar mass of hydrogen}=(0.400mole)\times (1g/mole)=0.4g[/tex]
Now we have to calculate the mass of oxygen.
Total mass of unknown compound = Mass of carbon + Mass of hydrogen + Mass of oxygen
6.00 = 2.4 + 0.4 + Mass of oxygen
Mass of oxygen = 3.2 grams
Now we have tom calculate the moles of oxygen.
[tex]\text{Moles of oxygen}=\frac{\text{Mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{3.2g}{16g/mole}=0.2moles[/tex]
Therefore, the moles of oxygen present in the sample is, 0.2 moles
