Question

What are the mass % of C₁₀H₁₄O for the individual elements. Keep all answers to the first decimal place?

also, how many grams of oxygen would be present in a 375.3 g sample of this compound?

and how many oxygen atoms would that be?

Answer 1

The molecular formula C₁₀H₁₄O has Molar Mass = 150.22 g/mol

Mass % = $\dfrac{mass of individual compound}{total mass of compound}$

Number of moles of compound = $\dfrac{375.3}{150.22}$

= 2.49 mol

Hence mass of oxygen = $2.49\times 16$

= 39.97 g

Number of oxygen atom = $39.97\times 6.022\times 10^{23}$

= $240.71\times 10^{23}$