Problem 123
How many oxygen atoms are contained in \(10.00 \mathrm{~g}\) of \(\mathrm{H}_{3} \mathrm{PO}_{4}\) ?
Problem 124
Calculate the mass percent of each element in \(\mathrm{Na}_{2} \mathrm{CO}_{3}\).
Problem 127
Vanillin, the active component of the flavoring vanilla, has the composition \(63.15 \% \mathrm{C}, 5.30 \% \mathrm{H}\), and \(31.55 \% \mathrm{O}\). (a) What is its empirical formula? (b) If the molar mass of vanillin is \(152.14 \mathrm{~g} / \mathrm{mol}\), what is its molecular formula?
Problem 128
Monosodium glutamate, \(\mathrm{NaC}_{5} \mathrm{H}_{8} \mathrm{NO}_{4}\), is used extensively as a flavor enhancer. What is its percent composition?
Problem 129
If \(5.00 \mathrm{~g}\) of \(\mathrm{Al}\) is burned completely in excess oxygen gas, \(9.45 \mathrm{~g}\) of an aluminum oxide is formed. What is the empirical formula of that oxide?
Problem 130
If \(4.32 \mathrm{~g}\) of \(\mathrm{Cu}\) combines with \(1.09 \mathrm{~g}\) of \(\mathrm{S}\) to form \(5.41 \mathrm{~g}\) of the bluish-black mineral chalcocite, what is the empirical formula of chalcocite?
