Two students analyze separate pure samples of the same unknown compound
CHEMISTRY · Single correct · CBSE · Chemistry · Some Basic Concepts of Chemistry · Some Basic Concepts of Chemistry
Problem
Two students analyze separate pure samples of the same unknown compound. Student A determines that a 13.50 g sample contains 8.10 g of bromine and the remainder carbon. Student B finds that a 9.00 g sample contains 5.40 g of bromine. Which of the following statements is most consistent with these data?
(a) The samples contain different compounds because the ratio of bromine to carbon mass is 8.10:5.40 in sample A but 5.40:3.60 in sample B.
(b) Both samples have essentially identical percent compositions, supporting that they are the same pure compound.
(c) The data illustrate the law of multiple proportions, showing that even though the percent composition is constant, the compounds are different.
(d) Because the two samples have different masses, their percent compositions cannot be compared directly, so no conclusion can be made about their identity.