Determining composition of unknown materials
The composition of a mixture may contain a variety of unknown components. In some cases, the components of a mixture may be known but the exact quantities are not. Analytical chemists have a variety of tools and techniques to analyze unknown substances and arrive at conclusions on the compounds/percentages in the mixture. Students will determine the percentage composition of sodium carbonate and sodium bicarbonate in an unknown sample. The mixture is heated vigorously until the sodium bicarbonate is completely decomposed to sodium carbonate. The only other products of the reaction are carbon dioxide and water. After performing the necessary calculations, students will determine the percentage of sodium bicarbonate that was present in their original sample. There are enough materials for 15 groups. Teacher’s manual and student copy masters are included.