Sometimes, during stress or trauma, a person can start to hyperventilate. Then the person might breathe into a paper bag to avoid fainting.

b. How does breathing into a paper bag help return blood pH to normal?

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Sometimes, during stress or trauma, a person can start to hyperventilate. Then the person might breathe into a paper bag to avoid fainting.

a. What changes occur in the blood pH during hyperventilation?

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Obtain a package of Alka-Seltzer, an antacid, from the local drug store:

b. Why does Alka-Seltzer foam and bubble when dissolved in water? Which ingredient is the antacid?