chapter 11 water and solutions. 2 homework for chap 11 read p 275 – 280; 284 - 290 applying the...
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Chapter 11
Water and Solutions
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Homework for Chap 11Homework for Chap 11
Read p 275 – 280; 284 - 290
Applying the Concepts # 1 – 3; 9 - 24
Fig. 11.2 (A) The water molecule is polar (It has a dipole.)
H2O
Fig. 11.2 (B) Attractions between water molecules
Ice is less dense than water
Water is a Unique Substance:
Fig. 11.3 The hexagonal structure of ice
Maximum Density4 °C
Density of Water
Fig. 11.4 The density of water just above its freezing point
Solution - a homogenous mixture of 2 or more substances
Solute - the substance(s) present in the smaller amount(s)
Solvent - the substance present in the larger amount
Solution Solvent Solute
Soft drink (l)
Air (g)
Soft Solder (s)
H2O
N2
Pb
Sugar, CO2
O2, Ar, CH4
Sn
Fig 11.6 NaCl dissolving in water
Fig. 11.10 Behavior of electrolytes and nonelectrolytes.
Electrolyte - a substance that, when dissolved in water, forms a solution that can conduct electricity.
Nonelectrolyte - a substance that, when dissolved, forms a solution that does not conduct electricity.
nonelectrolytestrong electrolyte
Fig. 11.11 The reaction of water and hydrogen chloride
Hydronium ion
Acids, Bases, and Salts
acid + base salt + water
HCl (aq) + NaOH (aq) NaCl (aq) + H2O
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Acids
1. Have a sour taste. e.g., Vinegar, lemons, limes, sour milk
2. Cause litmus to change from blue to red.
4. Acid solutions conduct electricity.
3. Acids neutralize bases.
Fig 11.14 (A)
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1. Have a bitter taste. e.g., caffeine, walnuts, soap
3. Feel slippery. Many soaps contain bases.
Bases
5. Basic solutions conduct electricity.
2. Cause litmus to change from red to blue.
4. Bases neutralize acids.
Fig 11.14 (B)
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How do we express the concentration
of an acid or a base?
pH scale – based on concentration of the
hydronium ion (H3O+)
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
acidic basicneutral
Based on powers of 10:
e.g., a soln with pH = 3 is 10 times moreacidic than a solution with pH = 4
Fig. 11.16 Common substances that are acidic
Table 11.5Approximate pH of some common substances