8. Potassium persulphate (Anthion) is used in photography to remove the last traces of hypo from photographic papers and plates. A 0.8162 gram sample was found to k: 39 contain 0.2361 grams of potassium and 0.1936 grams of sulphur; the rest was s = 32.0 oxygen. The molecular mass of this compound was measured to be 270.3 u. What are the empirical and molecular formulas of potassium persulphate? (Arrange the atomic symbols in the formulas in the order KSO.)

4.79 Phosphoric add (H3PO4) is important in the production of both fertilizers and detergents. It is distributed commercially as a solution with a concentration of about 14.8 M. Approximately 2.1 X l09 gallons of this concentrated phosphoric acid solution is produced annually in the United States. Assuming that all of this H3PO4 is produced by the reaction below, what mass of the mineral fluoruapatite (Ca5(PO4)3F) would be required each year? Ca5( PO4)3F+5H2SO43H3PO4+5CaSO4+HF

Many cereals are made with high moisture content so that the cereal can be formed into various shapes before it is dried. A cereal product containing 58% H2O by mass is produced at the rate of 1000. kg/h. What mass of water must be evaporated per hour if the final product contains only 20.% water?

3.122 What type of reasoning were we using when we developed the equation for dilution, MiVi=MfVf ?

Tungsten (W) metal, which is used to make incandescent bulb filaments, is produced by the reaction WO3+3H23H2O+W How many grams of H2 are needed to produce 1.00 g of W?

A chemist prepared a compound that she thought had the formula FeI3. When the compound was analyzed, it contained 18.0% Fe and 82.0% I. Calculate the mass percentage composition expected for FeI3 and compare the result with that found in the analysis. Is this the correct formula of the compound?

3.120 1f you have 32.6 g of sodium carbonate that is dissolved to give 2.10 L of solution, what is the molarity of the solution? What is the molarity of the sodium ions?

Silicon is produced for the chemical and electronics industries by the following reactions. Give the balanced equation for each reaction. a. SiO2(s)+C(s)arefurnaceElectricSi(s)+CO(g) b. Liquid silicon tetrachloride is reacted with very pure solid magnesium, producing solid silicon and solid magnesium chloride. c. Na2SiF6(s) + Na(s) Si(s) + NaF(s)

A common method for analyzing for the nickel content of a sample is to use a precipitation reaction. Adding the organic compound dimethylgly-oxime to a solution containing Ni2+ ions precipitates a red solid. Derive the empirical formula for the red solid based on the following composition: Ni, 20.315%; C, 33.258%; H, 4.884%; 0, 22.151%; and N, 19.392%.