Name __________________________________ Hour _____ Solutions Homework 1. What is the solvent and what is the solute in MgF2 (aq)? 2. DRAW what is happening at the molecular level when KBr is dissolved in water. 3. What is the general solubility rule? Using that rule, what do you know is true about the polarity of oil? Hint: think of an oil/water mixture. 4. Draw molecules in the boxes below to help understand concentration. Less concentrated solution 5. What is the difference between a concentrated and dilute solution? 6. Describe how to make a solution. 7. Describe how to dilute a solution. 8. Define the following terms: a. Saturated solution b. Supersaturated solution c. Unsaturated solution More concentrated solution 9. How does temperature generally affect solubility? 10. Explain why salt is thrown on icy roads in the winter. Be specific about what is happening at the molecular level. 11. What happens to the boiling temperature of a substance when the amount of solute increases? Use the diagram below to answer questions 12-15 12. List the following solutions as saturated, unsaturated, or supersaturated a. 70 g of CaCl2 at 30°C __________________ b. 50 g of KCl at 60°C ___________________ c. 20 g KNO3 at 30°C ____________________ d. 30 g of K2Cr2O7 at 50°C ________________ 13. The temperature must be at least _____________ to dissolve 90 g of KNO3 into 100 g of water. 14. Why is Ce2(SO4)3 different than all of the other compounds on the solubility chart? 15. I have 20 grams of KCl dissolved into 100 g of water at 70°C. About how many more grams of KCl can be dissolved in the water to make it a saturated solution? Molarity/ problems 16. Fill in the equation circle to the right. What are the units for concentration?_________ or ______ Volume must be measured in the units ______. 1 L = _______ mL 17. What is the concentration of a solution when 0.77 moles of NaCl is dissolved into water to make 1.2 L of solution? 18. A 250 ml solution is made with 0.50 moles of KBr. What is the molarity of the solution? 19. What is the volume of a 0.25M solution that contains 2.2 moles of solute? 20. How many moles KClO3 are in 30 mL of a 0.100 M solution? How many grams? 21. Calculate the molarity of the following solutions a. 1.5 g of NaCl is dissolved in water to make 250 mL of solution b. 0.4 g of NaOH is dissolved in water to make 150 mL of solution 22. How many moles of AlCl3 are in 100 mL of a 0.50M solution? 23. How many moles of Ca(OH)2 are in 25 mL of 1.5M solution? 24. A reaction calls for the use of 5.00 mol of NH4OH. You have a bottle of 1.5M NH4OH. How many milliters of the solution should you add? 25. A reaction calls for the use of 0.33 mol H2SO4. You have a bottle of 0.1M H2SO4. How many mL should you add? 26. How many grams of CaCl2 would be required to produce a 3.5 M (molar) solution with a volume of 2.0 L? 27. How many moles of Sr(NO3)2 would be used in the preparation of 2.50 L of a 3.5 M solution? 28. What is the volume of 3.0 M solution of NaCl made with 526g of solute? 29. If you evaporate 32 mL of a 0.50 M CuSO4 to dryness, how many grams of solid copper sulfate would be left on the bottom of the beaker? 30. A 4 g sugar cube (sucrose: C12H22O11) is dissolved in a 350 ml teacup filled with hot water. What is the molarity of the sugar solution? Dilution problems 31. What is the new volume of a 200 mL solution of 0.5M NaOH diluted to 0.1 M NaOH? 32. Calculate the moles of 1 M NaOH aqueous solution needed to make 100 mL of 0.5 M NaOH aqueous solution. 33. If I dilute 250 mL of 0.10 M lithium acetate solution to a volume of 750 mL, what will the concentration of this solution be? 34. What would be the concentration of a solution made by diluting 45.0 mL of 4.2 M KOH to 250 mL? 35. If I have 340 mL of a 0.5 M NaBr solution, what will the concentration be if I add 560 mL more water to it?