IPS: Chapter 4 Quiz
(4.9-Acidification Lab)
Acid Rain & Global Warning
- CO2, Sulfuric Acid, Hydrogen Chloride --> create an acidic solution
- Carbonic Acid --> dissolved CO2 in rain water
- Sulfuric Dioxide --> "acid rain"
- ( ex: Volcanoes and Industrial Pollution) (ex: Kill Forest and Pollute Water... river, lake, pond)
Limestone and Sinkholes
Limestone:
- Porous (hold H2O)
- Soft
- Soluble in H2O (Carbonic Acid)
Florida Sinkholes Occur Because:
- Lots of Limestone
- Water underground (aquifer)
- Once covered with ocean --> soft calcium
Sulfuric Acid
Discovered in 8th century by Alchemist --> alchemy "chemistry"
Uses:
- Lead acid batteries (cars)
- Fertilizers
- Steel industry --> prevents rust corrosions
- Dried fruit production (hydrotropic)
2 Gases Post Lab
Mr. Leed's Experiment:
- Magnesium Carbonate + Sulfuric Acid= CO2
- CO2 is MORE dense than air
- Therefore, CO2 stays in the upright test tube and leaves in the inverted test tube
- CO2 isn't flammable
- Therefore, the flame stick burns out fast in upright test tube and stays lit in the inverted test tube (because classroom air has replaced CO2)
My Experiment:
- Magnesium + Sulfuric Acid= Hydrogen
- Hydrogen is LESS dense than air
- Therefore, hydrogen leaves the upright test tube and stays in the inverted test tube
- Hydrogen is flammable
- Therefore, the flame stick stays lit (because of air) in the upright test tube and pops in the inverted test tube (because hydrogen is less dense, so it doesn't fill with class room air, so it hasn't been replaced)
The "popping noise" is from when the gas is ignited and rushes out of the test tube and rubs agains the glass causes friction (sound)
Experimental Errors:
- Not waiting 30 seconds
- Unstopper before inverting
- Break surface H2O with test tube
- Don't collect full test tube of gas
- Air bubble in test tube
- Stoppers not tight
- Not keeping test tubes vertical
Acidification Post Lab
Phenol Red changes color as you add CO2 into H2O
The CO2 turns to carbonic acid lowering the PH of the H2O
Calcium tablet is more soluble in cup with straw
Because the carbonic acid lowers PH and dissolves calcium faster
Experimental Errors:
- Not enough Phenol scale
- Don't bubble H2O long enough
- 2 cups don't have sam amount H2O
- Lose water when using straw
- Put CO2 into both cups
Ocean Acidification:
- Oceans PH has decreased 0.1
- About 25% drop in PH
- ^^ Normal ocean PH: 8.0-8.4
- Lower PH will cause shelled animals (shrimp, mollusks) to not be able to build a shell