4.9 QUIZ

Acidification Lab and 2 Gases Lab




Part I

1. Fill cup to first ridge in plastic

2. Put 1 full dropper of indicator into water

3. Record color

4. Without straw, exhale onto top of water for about 2 minutes

5. Record color

6. Use straw to blow bubbles into water for about 1 minute

7. Record color

Part II

1. Fill 2 cups with H2O to top of bottom section of ridges

2. Put calcium tablet in each cup

3. Blow bubbles for 5 minutes in one cup

4. Let H2O settle

5. Compare tablets

Experimental Errors

  • Don't bubble water enough (not enough carbon dioxide)
  • 2 cups don't have same amount of water
  • Lose water when using straw
  • Put carbon dioxide in both cups



I. Gas Collection

1. Set-up pegboard

a) Fill container a little more than halfway with water

b) Invert four test tubes filled with water

2. Put 5 pieces of magnesium into large test tube first

3. Mr. Leeds checks set-up

4. Pour 25 cm3 of acid into test tube

5. Stopper quickly and inset tubing into first test tube

6. Collect test tubes of gas (stopper tightly)

II. Clean Up

1. Keep gloves, aprons, and goggles on

2. Pour acid and magnesium into sink

3. Rinse out test tube, stopper, and tubing,

4. Throw magnesium in trash

III. Flame Test

1. Hold 2 test tubes, one upright and one inverted

2. Remove stoppers, wait 30 seconds

3. Light flame stick and insert into test tube

4. Repeat with two more test tubes

5. Repeat flame test with classroom air

Experimental Errors

  • Not waiting 30 seconds
  • Unstopper before inverting
  • Break surface of water with test tube
  • Don't collect full test tube of gas
  • Air bubble in test tube
  • Stopper not tight enough
  • Not keep test tubes vertical


  • Normal ocean pH is 8.1-8.14
  • Ocean's pH has decrease 0.1 (about 25% decrease)
  • Lower ocean pH means sea animals with shells will not be able to make a shell (crabs, shrimp, clams, etc.)