Chapter 3

Last update by Smcdonald1 on 09/18/2014
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Buffers are substances that help resist shifts in pH by

A) releasing H+in acidic solutions.

B) donating H+to a solution when they have been depleted.

C) releasing OH-in basic solutions.

D) accepting H+when the are in excess.

E) Both B and D are correct.

Answer:
E) Both B and D are correct.

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    Answered in Chapter 3

    One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3).

    Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion

    (H+). Thus,

    H2CO3 HCO3-+ H+


    If the pH of the blood drops, one would expect

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    B) the concentration of hydroxide ion (OH-) to increase.

    C) the concentration of bicarbonate ion (HCO3-) to increase.

    D) the HCO3-to act as a base and remove excess H+with the formation ofH2CO3.

    E) the HCO3-to act as an acid and remove excess H+with the formation of H2CO3.



    D) the HCO3-to act as a base and remove excess H+with the formation ofH2CO3
  • feldman2009
    Answered in Chapter 3

    One of the buffers that contribute to pH stability in human blood is carbonic acid H2CO3.

    Carbonicacid is a weak acid that when placed in an aqueous solution dissociates into a

    bicarbonate ion (HCO3-) and a hydrogen ion (H+). Thus,

    H2CO3 HCO3-+ H+


    If the pH of the blood increases, one would expect

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    D) an increase in the concentration of HCO3-and a decrease in the concentration of H2O.

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    A) a decrease in the concentration of H2CO3andan increase in the concentration of H2O.
  • feldman2009
    Answered in Chapter 3

    Assume that acid rain haslowered the pH of a particular lake to pH 4.0. What is the hydroxylion concentration of this lake?

    A) 1 × 10-10mol of hydroxyl ion per liter of lake water

    B) 1 × 10-4mol of hydroxyl ion per liter of lake water

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  • feldman2009
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    Research indicates that acid precipitation can damage living organisms by

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    B) decreasing the H+concentration of lakes and streams.

    C) increasing the OH-concentration of lakes and streams.

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    Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From thisinformation, we can reasonably conclude that

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    Answered in Chapter 3

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