It 150 Worksheet by kgs75263


More Info

Chem 150                                           Worksheet on Solution Concentrations
Use significant figures.

Recall:           solute = component of the mixture you are interested in (other than the solvent)

                  solvent = the major substance in the mixture                                   solution = the entire mixture

                                               mass of solute                                                               1g of solute
                  mass percent (% m/m) =                                 100%                   mass fraction (ppm) =
                                             mass of solution                                                              6
                                                                                                                         10 g of solution
                                                                                                 (ppb=109; ppt=1012)

                                               volumeof solute                                                    moles of solute
                  volume percent (% v/v) =                                 100%                 Molality (m) =
                                              volumeof solution                                                    kg of solvent

                                                                 mass of solute(g)                                 moles of solute
                  mass-volume percent (% m/v) =                                                  Molarity (M) =
                                                                   mL solution                                      L of solution

     1. If you have a 5.0% (m/m) solution of                                               3. Whole milk (homogenized) contains 3.6%
        NaHCO3, how much solute is in 100. grams                                              (m/m) butterfat. How many grams of fat is
        of solution?                                                                          in a cold glass of milk (8.00 fluid oz.)? The
                                                                                                 density of whole milk at 4ºC is 1.033 g/mL and 1 mL
                                                                                                 = 0.034 fl. oz.

     2. A typical intravenous solution used at the                                         4. If you make a solution by using 45 g sucrose
        hospital consists of 5.0% (m/v) dextrose                                           and add enough water to make 250. mL of
        (also called glucose). How many grams of                                           solution, what is the % (m/v) of this solution?
        dextrose is in 500. mL?

                                                                                           b. What is the molarity of this solution?
                                                                                           Sucrose is C12H22O11.
5. a. A bottle of cold medicine contains         7. To make tea, you dissolve 10.0 g of sugar
25%(v/v) ethyl alcohol (ethanol) in water. In    (about 1 heaping spoonful) in a cup of water
125 mL of medicine, how much ethyl alcohol is    (250.g). What are the mole fraction, molality,
there (in mL)?                                   and mass % of sugar (C12H22O11) in this cup of

b. Ethyl alcohol is C2H6O and has a density of
0.789 g/mL. What is the molarity of the
solution in Part A?                              8. Silver ion is found with an average
                                                 concentration of 28 ppb in U.S. water supplies.
                                                 (Assume the density of water is 1.0 g/cm3)

                                                 a) What is the molarity of the silver ion?

6) If the Dead Sea contains 4600 ppm bromide
ion, what is the molality of the ion?            b) If you wanted 1.0 x 102 g of silver and could
                                                 recover it chemically from water supplies, how
                                                 many liters of water would you have to treat?

                                                 Answers: 1) 5.0 g NaHCO3; 2) 25g dextrose; 3) 8.7g fat (yuck!); 4) a.
                                                 18%, b. 1.0M; 5) a. 31mL, b. 4.2M or 4.3M; 6) 0.058m; 7) 0.00210
                                                 mole fraction of sugar; 0.117m; 3.85% sugar; 8) a. 2.6x10-7M; b.

To top