1.4 Composition of Mixtures

1. Answer the following questions about the mixture whose composition is listed in the table above. (a) Calculate the percentage of NaCl by mass in this mixture. (b) Calculate the percentage of Na by mass in this mixture. (c) Calculate the percentage of Cl by mass in this mixture. 2. (b) Which of the following is more likely to represent the solid sample that was analyzed by the student? Justify your answer. a mixture of AgNO3 and AgCl a mixture of AgNO3 and AgBr 3. A student needs to analyze a mixture that contains BaCl2 and NaCl. The student dissolves a 6.75-g sample of this mixture completely into water and adds an excess amount of Na2SO4(aq). A white precipitate of BaSO4(s) is formed, based on the following chemical equation. BaCl2(aq) + Na2SO4(aq) → 2 NaCl(aq) + BaSO4(s) The solid precipitate is filtered, dried, and weighed, and its mass is recorded as 2.36 g. (a) Calculate the number of moles of BaSO4(s) that is recovered in this experiment. (b) Calculate the percentage of BaCl2 by mass in this mixture. 4. A mixture of CaCO3 and Na2CO3 is found to contain 35.00% Na by mass. Calculate the percentage of Na2CO3 by mass in this mixture.