Problem 73
Ereon is a trade name for a group of gaseous compounds once used as propellants in aerosol cans. Which has a higher percentage of chlorine: Freon-12 \(\left(\mathrm{CCl}_{2} \mathrm{~F}_{2}\right)\) or Freon-141b \(\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{Cl}_{2} \mathrm{~F}\right) ?\)
Problem 74
Which has a higher percentage of fluorine: Freon-12 \(\left(\mathrm{CCl}_{2} \mathrm{~F}_{2}\right)\) or Freon \(113\left(\mathrm{C}_{2} \mathrm{Cl}_{3} \mathrm{~F}_{3}\right) ?\)
Problem 75
It was found that \(2.35 \mathrm{~g}\) of a compound of phosphorus and chlorine contained \(0.539 \mathrm{~g}\) of phosphorus. What are the percentages by mass of phosphorus and chlorine in this compound?
Problem 76
An analysis revealed that \(5.67 \mathrm{~g}\) of a compound of nitrogen and oxygen contained \(1.47 \mathrm{~g}\) of nitrogen. What are the percentages by mass of nitrogen and oxygen in this compound?
Problem 77
Phencyclidine ("angel dust") is \(\mathrm{C}_{17} \mathrm{H}_{25} \mathrm{~N}\). A sample suspected of being this illicit drug was found to have a percentage composition of \(84.71 \% \mathrm{C}, 10.42 \% \mathrm{H},\) and \(5.61 \% \mathrm{~N}\). Do these data acceptably match the theoretical data for phencyclidine?
Problem 78
The hallucinogenic drug LSD has the molecular formula \(\mathrm{C}_{20} \mathrm{H}_{25} \mathrm{~N}_{3} \mathrm{O} .\) One suspected sample contained \(74.07 \% \mathrm{C},\) \(7.95 \% \mathrm{H},\) and \(9.99 \% \mathrm{~N}\) (a) What is the percentage of \(\mathrm{O}\) in the sample? (b) Are these data consistent for \(L S D ?\)
Problem 79
How many grams of \(\mathrm{O}\) are combined with \(7.14 \times 10^{21}\) atoms of \(\mathrm{N}\) in the compound dinitrogen pentoxide?
Problem 80
How many grams of \(\mathrm{C}\) are combined with \(4.25 \times 10^{23}\) atoms of \(\mathrm{H}\) in the compound \(\mathrm{C}_{5} \mathrm{H}_{12} ?\)
Problem 81
Write empirical formulas for the following compounds. (a) \(\mathrm{S}_{2} \mathrm{Cl}_{2}\) (d) \(\mathrm{As}_{2} \mathrm{O}_{6}\) (b) \(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\) (e) \(\mathrm{H}_{2} \mathrm{O}_{2}\) (c) \(\mathrm{NH}_{3}\)
Problem 82
What are the empirical formulas of the following compounds? (a) \(\mathrm{C}_{2} \mathrm{H}_{4}(\mathrm{OH})_{2}\) (d) \(\mathrm{B}_{2} \mathrm{H}_{6}\) (b) \(\mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{8}\) (e) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\) (c) \(\mathrm{C}_{4} \mathrm{H}_{10}\)
