HW: Percent Composition

1. Use the following compound to answer the questions that follow: Sr3(PO4)2 a) What is the ratio of phosphorus atoms to oxygen atoms? 1:4b) How many phosphate ions? 2c) What is the oxidation number for the phosphate ion? -3 2a. Which has the larger percent by mass (percent composition) of sulfur, H2SO3 or H2S2O8? H2SO3 H2S2O8 2b. What is the percent composition of sulfur in the answer you chose in 2a? % S (to the hundredth place) = 39.06% 3. What percentage of water is found in AlCl3•6H2O? Show your work in the table below. Your answer goes into the top right box. Round to the hundredth place. x 100 44.78% blank blank 4. Review Compound Naming Formula Name AlPO4 aluminum phosphate CrO2 chromium (IV) oxide N2O4 dinitrogen tetraoxide Mg(OH)2 magnesium hydroxide HF hydrofluoric acid CaI2 calcium iodide PCl3 phosphorus trichloride 5. Review Compound Formulas To make a subscript, highlight the number and formatting options will pop up. Click on the subscript option (looks like x2). Name Formula calcium carbonate CaCO3 phosphoric acid H3PO4 ammonium sulfate (NH4)2SO4 sulfur dioxide SO2 aluminum nitride AlN platinum (I) phosphide Pt3P zinc nitrate Zn(NO3)2