Fundamentals of acids and bases.

1. Water self ionizes to a small extent creating equal concentrations of hydronium and hydroxide ions. What is the molar concentration of these ions in water at 25^oC?

a.  1.0 x 10^?1 moles/L      

b.  1.0 x 10^?9 moles/L

c.  1.0 x 10^?4 moles/L      

d.  1.0 x 10^?7 moles/L

e.  concentrations too small to measure reliably.

2.A solution contains a concentration of [H₃O⁺] = 1.0 x 10^?9 moles/L and a concentration of [OH^?] = 1.0 x 10^?5 moles/L. This solution is

a. acidic   

b.  basic  

c. neutral  

d. none of the above.

3.NaOH, lye, is a strong base. Concentrated sodium hydroxide  is extremely dangerous if ingested.  Mg(OH)₂ is also a strong base.  However, it is safely consumed as "milk of           magnesia" by millions daily.  Why?

a.  It is not ? the above statement is false.

b.  Excess hydroxide is consumed as hydrogen gas.

c.The low solubility of Mg(OH)₂ in water assures the hydroxide concentration remains low.          d. The high solubility of Mg(OH)₂ in water assures the magnesium hydroxide does not dissociate into hydroxide ions.

4. Under the Arrhenius definition an acid is

a.  a source of hydroxide ions.

b.  a source of hydrogen ions.

c.  a proton acceptor

d.  a nonelectrolyte

5.  What is the pH of a solution with a hydronium ion concentration of 2.51 x 10^?6

a.   1.21

b.   4.26

c. 14.00

d.   5.60

e. none of the above.

6.   A sample of gas is warmed from 15.0 ^oC to 45.0 ^oC at a  constant pressure.Its initial volume is 1.75 liters.  What is the final volume of the gas.

a.  5.25 L  

b.  1.58 L  

c.  1.84 L   

d.  1.93 L

e.  None of the above.

7. Which of the following statements is not true of the Kinetic Molecular Theory and the Ideal Gas Law:

a.  Molecules are assumed to be point masses.

b.  Collisions between molecules are elastic.

c.  The molecules of a gas are in constant chaotic motion.

d.  The temperature of a gas is directly proportional to the most probable kinetic energy of a sample of molecules.

e.  There are assumed to be intermolecular forces between gas molecules.

8. At constant pressure in a sealed system the volume of the gas is directly proportional to its absolute temperature.  This is known  as (the)

a.  Boyle's law.             

b.  Dalton's law.

c.  Charles' law.            

d.  ideal gas law.

e.  none of the above.

9. A mixture of oxygen, hydrogen, nitrogen and carbon dioxide   in a two liter flask has a total pressure of 1.251 atm. The partial pressure of oxygen, hydrogen, and nitrogen are 0.210, 0.145, and 0.235 atm, respectively.  Use Dalton's  Law of partial pressures to determine the partial pressure of the carbon dioxide.

a.  0.590  atm.         

b.  0.661  atm.

c.  1.251  atm.         

d.  0.551  atm.

e.  none of the above.

10.  A strong electrolyte generates

a.  a high percentage of ionization in solution.

b.  a low percentage of ionization in solution.

c.  essentially zero ionization in solution.

d.  low solubility in a basic solution.

11.Under the Arrhenius definition an base is

a.  a source of hydroxide ions.

b.  a proton donor

c.  a proton acceptor

d.  a nonelectrolyte

12. What is the volume (in L) of 15.0 g of HBr gas at 715 torr and  90.0 ^oC?  (hint: calculate the number of moles of HBr).

a.  13.0                     

b.  6.51

c.  9.79                     

d.  5.87

e.  none of the above.