Name:______
Hour: ______
Chapter 4: Aqueous Reactions and Solution Stoichiometry
Reading Guide: Section 4.1: General Properties of Aqueous Solutions (Pg 122)
1. A ______is a homogeneous mixture of two or more substances.
2. The substance present in greatest quantity is usually called the ______.
3. The other substances in the solution are known as the ______; they are said to be dissolved in the solvent.
Electrolytic Properties
4. What is one way that a solution of salt water and a solution of sugar water are different? ______. The salt solution is a good conductor of ______, whereas the sugar solution is not.
5. Although water itself is a poor conductor of electricity, the presence of ______causes aqueous solutions to become good conductors.
6. ______carry electrical charge from one electrode to the other, completing the electrical circuit.
7. Thus, the conductivity of ______solutions indicates the presence of ions in the solution, and the lack of conductivity of ______solutions indicates the absence of ions in solution.
8. When NaCl dissolves in water, the solution contains ______and ______ions, each surrounded by water molecules.
9. When sucrose dissolves in water, the solution contains only ______sucrose molecules surrounded by water.
10. A substance whose aqueous solutions contain ions is called an ______.
11. A substance that does not form ions in solution is called al ______.
12. The difference between NaCl and C12H22O11 arises largely because NaCl is ______and C12H22O11 is ______.
Ionic Compounds in Water
13. The ionic solid ______into its component ions as it dissolves.
14. Water is a very effective ______for ionic compounds.
15. Although water is electrically neutral molecule, one end of the molecule is rich in ______and thus possesses a partial ______charge, denoted by ______.
16. The other end has a partial ______charge, denoted by ______.
17. Positive ions called ______are attracted to the negative end of water, and negative ions called ______are attracted by the positive end.
18. Draw the water molecule diagram shown on the right margin (under the figure 4.2, to the right of the text) showing the partial negative and partial positive regions of water:
19. As an ionic compound ______, the ions become surrounded by water molecules. The ions are said to be ______.
20. The ______process helps stabilize the ions in solution and prevents ______and ______from recombining.
21. Furthermore, because the ions and their shells of surrounding water molecules are free to move about, the ions become ______uniformly throughout the solution.
22. We can usually predict the nature of the ions present in a solution of an ionic compound from the ______of the substance.
23. Sodium sulfate ( ______), for example, dissociates into ______ions (______) and ______ions (______).
24. You must remember the ______and ______of common ions to understand the forms in which ionic compounds exist in aqueous solution.
25. Give it some thought: What dissolved species are present in a solution of
- KCN ______and ______ions
- NaClO4 ______and ______ions
Molecular Compounds in Water
26. When a molecular compound dissolves in water, the solution usually consists of ______dispersed throughout the solution.
27. Consequently, most molecular compounds are ______.
28. There are, however, a few molecular substances whose aqueous solutions contain ______.
29. The most important of these are ______.
30. For example, when HCl (g) dissolves in water to form hydrochloric acid, HCl (aq), it ______; that is, it dissociates into ______and ______ions.
Strong and Weak Electrolytes
31. There are two categories of electrolytes, ______and ______, which differ in the extent to which they conduct electricity.
32. ______are those solutes that exist in solution completely or nearly completely as ions.
33. Essentially all soluble ______and a few molecular compounds (such as ______) are strong electrolytes.
34. ______are those solutes that exist in solution mostly in the form of molecules with only a small fraction in the form of ions.
35. For example, in a solution of ______(______) most of the solute is present as ______molecules.
36. Only a small fraction (about ______) of the ______is present as ______and ______ions.
37. We must be careful not to confuse the extent to which an electrolyte ______as either strong or weak.
38. For example, ______is extremely soluble in water but is a weak electrolyte.
39. ______, on the other hand, is not very soluble, but the amount of the substance that does dissolve dissociates almost ______, so ______is a strong electrolyte.
40. When a weak electrolyte such as acetic acid ionizes in solution, we write the reaction in the following manner: ______.
41. The double arrow means that the reaction is significant in ______directions.
42. At any given moment some ______molecules are ionizing to form ______and ______. At the same time, ______and ______ions are recombining to form ______.
43. The balance between these opposing processes determines the relative number of ______and neutral ______.
44. This balance produces a state of ______that varies from one weak electrolyte to another.
45. Chemists use a ______to represent the ionization of weak electrolytes and a ______to represent the ionization of strong electrolytes.
46. Because HCl is a strong electrolyte, we write the equation for the ionization of HCl as follows: ______.
47. The absence of a reverse arrow indicates that the ______and ______ions have no tendency to ______and form HCl molecules.
48. In the sections ahead we will begin to look more closely at how we can use the composition of a compound to predict whether it is a ______electrolyte, ______electrolyte, or ______electrolyte.
49. For the moment, it is important only to remember that ______are strong electrolytes.
50. We identify ionic compounds as being ones composed of ______and ______, or compounds containing the ______ion.
51. Give it some thought: Which solute will cause the light bulb in the experiment shown in Figure 4.2 to glow more brightly, CH3OH or MgBr2? ______
Sample Exercise 4.1 Relating Relative Numbers of Anions and Cations to Chemical Formulas (Pg 125)
The diagram on the right represents an aqueous solution of one of the following compounds: MgCl2, KCl, K2SO4. Which solution does it best represent and WHY?
Draw diagrams (such as that above) representing aqueous solutions of each of the following ionic compounds such that each contains 6 cations and the appropriate number of anions:
NiSO4 / Ca(NO3)2Na3PO4 / Al2(SO4)3
Distributed Practice:
1. A strip of zinc metal having a mass of 2.00 g is placed in an aqueous solution containing 2.50 g of silver nitrate.
- Write the balanced chemical reaction:
- Which reactant is the limiting reagent? Justify your answer with both a mathematical calculation and using a sentence that explains your choice.
- How many grams of Ag will form?
- How many grams of the excess reactant will be left at the end of the reaction?
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