posted by Katie .
1- A compound is 87.5% nitrogen and 12.5% hydrogen. The molecular weight of the compound is 32 g/mol. Describe the molecule referencing shape, and inter-molecular forces.
2- Gaseous butadiene, C4H6 , reacts with hydrogen gas in the presence of a platinum catalyst to form butane, C4H10 according to
C4H6 (g) +2 H2 → C4H10 (g)
A mixture of C4H6 and H2 known only to contain more H2 than C4H6 had a pressure of 74 mm Hg in an unknown volume. After the gas had been passed over the platinum catalyst, its pressure was 44 mm Hg in the same volume and temperature. What fraction of the molecules in the original mixture was butadiene?
3- A gaseous compound that only contains carbon, hydrogen, and sulfur is burned with oxygen under such conditions that the individual volume of the reactants and products can be measured at the same temperature and pressure. It is found that 3 volumes of the compound react with oxygen to yield 3 volumes of CO2 , 3 volumes of SO2 , and 6 volumes of water vapor. What volume of oxygen is required for combustion? What is the formula of the compound? Is this an empirical formula or a molecular formula?
4- A mixture of methane, CH4 and acetylene, C2H2 , occupied an unknown volume at a total pressure of 63 mm Hg. The sample was and the CO2 was collected. Its’ pressure was found to be 96 mm Hg in the same volume and temperature as the original mixture. What was the fraction of methane in the mixture?
5- A mixture of chromium and zinc metal weighing 0.362 gm was reacted with excess hydrochloric acid. After all of the metal reacted, 225 ml of dry hydrogen gas was collected at 27o C and 750 torr. Determine the mass percent of zinc in the mixture. Hint: Zinc reacts with HCl to produce zinc chloride and hydrogen gas. Chromium reacts with HCl to produce chromium(III)chloride and hydrogen gas.