Name:  _____________________                              date:  __________________               period: _______

Ch. 15 solution                                    test                              55 points (5 ec)                                                chemistry

In problems involving any calculation, show your work in an organized manner, include (i) any relevant equation (or formula), (ii) conversion factor(s), (iii) put the proper units in your calculations and answer, and (iv) have the proper number of significant figures in your answer.

1.  How to prepare a 275 mL aqueous solution of 325 mM glucose, C6H12O6 using __ ?  [10 points]

a. 500.0 mM aqueous solution of glucose

b. Solid glucose

2.  An aqueous solution contains 25.0 g of calcium nitrate and 125 mL of water; what is __ ?  [10 points]

a.  % calcium nitrate

b.  Molarity of calcium nitrate [assume that the density of the solution is 1.1 g / mL]

3.  A 125 mL aqueous solution of calcium chloride forms 1.5 g precipitate due to the addition of excess sodium phosphate; what was the concentration of calcium ions before the addition of sodium phosphate ?  [10 points]

4.  Mixing aqueous solutions of 35.0 mL of 25.0 mM Ca(NO3)2 and 75.0 mL of 10.0 mM Na3PO4 forms __ grams of Ca3(PO4)2.  [15 points]

5. If it takes 35.0 mL of a 75 mM sodium hydroxide to titrate 125 mL of sulfuric acid, H2SO4, what was the concentration of sulfuric acid before the titration ?  [5 points]

6. In the redox titration: 14 H + + 2 Mn 2+ + 5 NaBiO3 --> 2 MnO4 - + 5 Bi 3+ + 5 Na + + 7 H2O

At the equivalence point, it took 25 mL of 75 mM Mn +2  to react with 125 mL NaBiO3  -  what is the [NaBiO3] prior to the titration ?  [10 points]