UNIT 12 REVIEW

Part 1 – Solubility Curves – Use the solubility curve graph given with the Unit 12 materials to answer questions 1 - 4.

1.  At what temperature does 135 grams of KI dissolved in 100 grams of water form a saturated solution?

Approx. 10oC

2.  How many grams of KNO3 will dissolve in 400 grams of water at 60oC?
110 g KNO3 =   x g           x = 440 g
100 g H2O      400 g

3.  If 10 grams of KClO3 are dissolved in 100 grams of water at 30oC, is the solution saturated, unsaturated, or supersaturated?

unsaturated

4.  How many grams of solid precipitate will form if a saturated NaNO3 solution is cooled from 80oC to 20oC?

145 g – 87 g = 58 g

Part 2 – Concentration of Solutions

5.  How many grams of Fe(C2H3O2)3 are needed to dissolve to make 350. mL of a 2.50 M solution?

2.50 M =   x                        x = 0.875 moles Fe(C2H3O2)3                                                        Fe: 1 x 55.8 = 55.8

0.35 L                                                                                                                C:  6 x 12.0 = 72.0                  232.8

H:  9 x  1.0 =   9.0
0.875 moles Fe(C2H3O2)3  x  232.8 g Fe(C2H3O2)3   = 204 g                          O:  6 x 16.0 = 96.0

1 mole Fe(C2H3O2)3

6.  What is the molarity of a solution made by diluting 17.3 mL of 12 M hydrochloric acid to 550. mL?

12 M . 17.3 mL  = M2 . 550. mL                  M2 = 0.38 M

Part 3 – Solubility – Write (s) or (aq) next to each product.  Then, write the net ionic equation.

7.  ___ Ca(NO3)2 (aq)  +  ___ Na2CO3 (aq)  à  ___ NaNO3 (  aq  )  +  ___ CaCO3 (  s  )

N.I.E. = Ca+2 (aq)  +  CO3-2 (aq)
à  CaCO3 (s)
Spectator Ions = Na+1 and NO3-1

8.  ___ Zn(NO3)2 (aq)  +  ___ K3PO4 (aq)  à  ___ KNO3 (  aq  )  +  ___ Zn3(PO4)2 (  s  )

NIE =    3 Zn+2 (aq)  +  2 PO4-3 (aq)  à  Zn3(PO4)2 (s)
Spectator Ions = K+1 and NO3-1