Two flasks are connected by a valve. In flask 1 (of volume 8 D) is placed gas A. In flask 2 (of volume 11 L) is placed gas B. The apparatus is heated to and maintained at a constant temperature of 555 K. When the valve was opened, the following reaction occurred: 4A(g) + 3B(g) --> 4C(g) AFTER the reaction, the following data were collected: PA: 4 bar PB: O bar Pc 7 bar What was the pressure of gas A BEFORE the reaction? Give your answer in bar, and to at least 3 significant figures. Compound A has a molar mass of 157 grams, and compound B has a molar mass of 209 grams. A mixture of the two compounds was created which had a total mass of 13.8 grams. When the mixture was heated, compound A did not react. However, compound B decomposed: 3B(s) --> 2C(s) + 202(g) The Oz so generated was collected in a 9-l container over water at 20.36C, where the vapour pressure of water is 17.92 torr. If the total pressure (of water vapour and O2) collected was 76.96 torn, what was the percent by mass of compound A in the original mixture