91Ó°ÊÓ

A student attempts to identify an unknown compound by the method used in this experiment. She finds that when she heated a sample weighing 0.5015 g the mass went down appreciably, to 0.3432 g. When the product was converted to a chloride, the mass went up, to \(0.3726 \mathrm{g}\). a. Is the sample a carbonate? ______Give your reasoning. b. What are the two compounds that might be in the unknown? _______ and _______ c. Write the chemical cquation for the overall reaction that would occur when the original compound was converted to a chloride. If the compound is a hydrogen carbonate, use the sum of Reactions 1 and \(2 .\) If the sample is a carbonate, use Reaction \(2 .\) Write the equation for a sodium salt and then for a potassium salt. d. How many moles of the chloride salt would be produced from one mole of original compound? _______ e. How many grams of the chloride salt would be produced from one molar mass of original compound? Molar masses: \(\mathrm{NaHCO}_{3}\)______\(g\) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\)______\(g\) \(\mathrm{NaCl}\) _____ \(g\) \(\mathrm{KHCO}_{3}\) ______ \(g\) \(\mathrm{K}_{2} \mathrm{CO}_{3}\) _____ \(g\) \(\mathbf{K}_{2} \mathrm{CO}_{3}\) ____ \(g\) \(\mathrm{KCl}\) _____ \(g\)If a sodium salt, _______g original compound \(\rightarrow\) ______ g chloride If a potassium salt, _______g original compound \(\rightarrow\) ______ g chloride f. What is the theoretical value of \(\mathbf{Q}\) if she has an Na salt? ______ if she has a K salt? _____ g. What was the observed value of Q? ______ h. Which compound did she have as an unknown? ______