A 1.336-g sample of commercial contaminated by was dissolved in water, and the resulting solution was diluted to 500.0 mL. A 50.00-mL aliquot of this solution was treated with 40.00 mL of 0.05304 M and boiled to remove . The excess acid consumed 4.97 mL of 0.04809 M (phenolphthalein indicator). An excess of neutral was added to another 50.00-mL aliquot to precipitate the carbonate as . The solution was then titrated with 28.56 mL of the acid to a phenolphthalein end point. Calculate the percentage , , and in the sample, assuming that these are the only compounds present.

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size