Given 11.9 g Al what is the amount of Al in moles?

How many mols are there in each of the following samples? (convert grams to mols) a. 42 grams of the radioactive isotope Carbon-14

\( K ( SO _ { 3 } ) + HCl - SO _ { 2 } KCl + H _ { 2 } O \)

2. If a compound contains \( 40 \% \) sulfur and \( 60 \% \) oxygen by mass, what is the empirical formula of the compound? (Atomic masses: \( S=32 \mathrm{~g} / \mathrm{mol}, 0 \) \( =16 \mathrm{~g} / \mathrm{mol} \) )

Given 11.9 g Al what is the amount of Al in moles?

10. What is the percentage composition of oxygen in \( \mathrm{H}_{2} \mathrm{O} \) ? (Molar mass of \( \mathrm{H}_{2} \mathrm{O}=18 \mathrm{~g} / \mathrm{mol} ; \mathrm{O}=16 \mathrm{~g} / \mathrm{mol} \) )