3.09: Molar Mass of Compounds Purpose: Determining the Empirical Formula of a Tin Oxide Record the contents of the evaporating dish in the data table below. Item Mass, grams Evaporating Dish 19.508 G Evaporating Dish and two scoops of Tin 20.609 G Evaporating dish, Tin, and Nitric acid (before 20.609 G heating) Evaporating dish and compound (after heating) 20.212 G Observations Before the compound was heated the color was blue after it was heated the compound was white. Answer the following questions in your notebook so that you have them available when you take the quiz for this lesson. 1) The mass of tin in the evaporating dish remained constant throughout the experiment. This means that the mass change that any additional mass in the evaporating dish after the reaction is from the oxygen that bonded with the tin. Subtract the mass of the tin and dish from the mass of the compound and dish to determine the mass of the oxygen. Mass of oxygen = mass of Dish and compound – mass of Dish and Tin Mass of oxygen = 20.609 G – 20.212 G Mass of oxygen = 0.397 2) Solve for the mass of tin in the dish by subtracting the mass of the clean, empty dish in Step 1 from the mass of the tin and dish in Step 2. Mass of tin = mass of Dish and Tin – Mass of Dish Mass of tin = 20.609 G – 19.508 G Mass of tin = 1.101 G 3) Use the mass values of each element to determine the empirical formula of the tin oxide compound. Convert the mass of tin to moles of tin. 0.173 g/mol Convert the mass of oxygen to moles of oxygen. 0.003 g/mol Divide by the lowest mole value to get a whole number mole ratio. What is the formula for the hydrate? Because this is the empirical formula of an ionic compound, the empirical formula is also the formula unit. What is the full name (including Roman numeral) of this compound?