3 chemistry assignments due in 48 hours
Name ____________________________________ Date ____________ Period ____
Solution Concentration Problems
For each problem, choose the formula needed, write the formula, plug in values, and solve. Round to the least number of significant figures given in the problem. If you only write the final answer, you will not receive credit. Click HERE for a Periodic Table. Refer to the Video Lesson; Additional Examples; Textbook pp. 418-424
I. Using percent to describe concentration: Percent by mass = mass of solute x 100 Percent by volume = vol. of solute x 100
mass of soln. vol. of soln.
1. What is the percent by mass of potassium nitrate in a solution made by mixing 5.4 g of solute in 260.0 mL of water? (Density of H2O = 1.00 g/mL)
2. What is the percent by mass of sodium carbonate in a water solution containing 0.497 g Na2CO3 in 58.3 g of solution?
3. What is the percent by volume of isopropyl alcohol in a solution made by mixing 75mL of alcohol with enough water to make 288 mL of solution?
II. Molarity (M) = moles of solute Liter of soln.
1. What is the molarity of an aqueous solution that contains 18.2 g NaCl dissolved in 264 mL of the solution?
2. How many grams of NaCl are contained in 1.00 L of the solution from the previous problem?
Name ____________________________________ Date ____________ Period ____
3. What is the molarity of a solution is made by dissolving 17.0 g of lithium chloride (LiCl) in enough water to make 387mL of the solution?
4. Calculate the molarity of a water solution of CaCl2, given that 5.04 L of the solution contains 612 g of CaCl2.
III. Diluting a Solution M1V1 = M2V2
1. You are asked to make 0.879 L of 0.25M silver nitrate by diluting a stock solution of 0.675M silver nitrate. How many milliliters of the stock solution would you need to use? (Solve for V1).
2. If 55.0 mL of a 2.45 M stock solution of sucrose is diluted with water to make 168 mL of sucrose solution, what is the molarity of the final solution?
3. What volume, in milliliters, of a 1.15M stock solution of potassium nitrate is needed to make 0.75 L of 0.578 M KNO3?