Baird Chem in Your life Chapter 11
1. The only ionic solids that are not called salts are compounds ______.
a. in which the cation is H+ or anion is OH−
b. in which the cation is Mg2+
c. in which the anion is Cl1−
d. in which the cation is Na+
a: If the compound contains an H+ or an OH− than it is not a salt.
2. The common unit for solubility is ______.
a. grams/kilogram
b. moles/kilogram
c. grams/milligram
d. milligrams/gram
a: From page 409, solubility is in the form grams/kg.
3. What is a solution that is saturated?
a. the maximum amount of solute dissolved at a given temperature
b. any amount of solute dissolved in a solvent
c. more than the maximum amount of solute dissolved in a solvent
d. the maximum amount of solute dissolved at the boiling point of water
a: From page 409, this is the definition of saturated.
4. What are the ionic changes of the ions for Mg(OH)2 when this substance ionizes?
a. Mg2+, OH1−
b. Mg1+, OH2−
c. Mg1+, OH1−
d. Mg2+, OH2−
a: Mg is in group IIA, which will form a +2 ion, and OH is a −1 ion.
5. When seawater evaporates, what compounds are the first to precipitate?
a. calcium
b. magnesium
c. sodium
d. potassium
a: From Table 11.1, calcium forms insoluble salts with the lowest concentration.
6. What is the equivalent concentration of an ion that is 12ppm?
a. 12 mg/l
b. 1.2 mg/l
c. 12 g/l
d. 120 mg/l
a: From page 413, mg/l = ppm, see example.
7. What is the concentration in ppm of Ca2+ in a water sample having a concentration of 420 mg/L?
a. 420 ppm
b. 42 ppm
c. 4.20 ppm
d. 4200 ppm
a: From page 413, mg/l = ppm, see example.
8. What is the chemical form of fluoride that most North Americans receive from their toothpaste?
a. NaF
b. CaF2
c. Ca3(PO4)2
d. SiF6
a: From page 414, F is in the salt NaF.
9. What is a common characteristic of acids?
a. turn blue litmus red
b. turn red litmus blue
c. taste bitter
d. unreactive to metals
a: From page 416, see explanation.
10. Which of the following is considered a strong acid?
a. HCl
b. HNO2
c. H2CO3
d. HClO2
a: From page 418, HCl, HNO3,and H2SO4 are strong acids.
11. Calculate the molarity of an acid solution if there are 2.0 moles dissolved in 500 ml of water.
a. 4.0
b. 2.0
c. 8.0
d. 10.0
a: Molarity = moles/liter, therefore 2.0/.500 l = 4.0.
12. What is the pH of a solution if the concentration is 0.000010 moles/liter?
a. 5
b. 4
c. 9
d. 14
a: pH = −(log H+) = −(log 0f .00001) = −(−5) = +5
13. What is the H+ concentration in moles/liter if the pH of a solution is 9?
a. .000000001
b. .00009
c. .0000001
d. .000000009
a: pH = 9, which equates to the negative exponent −9 in base 10 = 10−9 = .000000001.
14. Which of the following is the most acidic?
a. lemon juice, pH = 2
b. oranges, pH = 4
c. soft drinks, pH = 3
d. vinegar, pH = 2.5
a: The lower the pH, the greater the acidity. It does not matter what the source of the H+ is.
15. Which of the following is a true statement for bases?
a. OH− concentration > than H+ concentration
b. reactive with metals
c. taste sour
d. OH− concentration < than H+ concentration
a: From page 428, definition of a base.