(2) Citric acid (H3C6H5O7) occurs in plants. The acid is added to beverages and candy. An aqueous solution is 0.710 m in citric acid. The density is 1.049 g/mL. Calculate the concentration of this solution as: (w/w %) (w/v %) M Mole Fraction (citric acid) 2
(3) When 75.0 mL of a 0.100 M lead (II) nitrate solution is mixed with 100.0 mL of a 0.190 M potassium iodide solution, a yellow-orange precipitate of lead (II) iodide is formed. a. Write the balanced molecular and net-ionic equation. b. Assuming 100% yield calculate the mass of lead (II) iodide formed. c. Determine the molarities of ions left in solution after the reaction.
(4) A 15.00 mL solution of KNO3 was diluted to 125.0 mL and 25.00 mL of this solution was then diluted to 1000. mL. The concentration of KNO3 in the 1000. mL is 0.00383 M. What was the M of KNO3 in the original solution? 3
(5) How many grams of pure H2SO4 can be obtained from 250 g of iron ore if the ore is 82.0 % (w/w %) FeS2. The reactions involved are given below: 4FeS2 + 11O2 â 2Fe2O3 + 8SO2 (95.0% efficient) 2SO2 + O2 â 2SO3 (90.0 % efficient) SO3 + H2O â H2SO4 (90.0 % efficient)
(6) 30.0 mL of 0.512 M sulfuric acid was added to 25.0 mL of 0.666 M sodium hydroxide. a. Write the balanced chemical equation. b. Determine the molarity of either acid or base remaining after the reaction. c. Find the molarity if a 50.00 mL aliquot of this solution is diluted to 250. mL.
(8) Oxygen is produced by the reaction: 2KClO3 (s) â2KCl (s) + 3O2 (g) ï· The oxygen produced was collected over water. A sample of KClO3 produced 705 mL of oxygen saturated with water vapor at 20.0 °C where the vapor pressure of water is 17.54 mm Hg. The total gas pressure was 1.104 atm. What mass of KClO3 decomposed?
(9) How many grams of C2H2 must burn according to the equation below in order to heat 2.34 à 104 g of H2O from 25.0 °C to 35.0 °C? C2H2 (g) + O2 (g) âH2O (l) + CO2 (g), Î = â 1212 kJ