4.9- Acidification Lab Study Guide

Quiz Monday 3/16

Acid Rain & Global Warming (4.9 Note)

Gasses dissolved in atmosphere: (ALL CREATE ACIDIC SOLUTION IN WATER)

- Carbon Dioxide

-Sulfur Dioxide

- Hydrogen Chloride



  • Carbon Dioxide dissolved in Water = CARBONIC ACID
  • Sulfur Dioxide = acid rain

- Caused by: volcanoes, hot springs, industrial pollution


- Causes: dead forests, polluted water

Limestone & Sinkholes

Limestone = porous, soft, soluble in water (with carbonic acid)


Sinkholes occur b/c:


  • Lots of limestone
  • Water underground (aquifer)
  • Once underwater -> soft calcium deposites (after evap.) from dead animals build up (sedimentary)



Snow melting picks up sediment/ mineral as it melts on mountain = large amounts of minerals (ex: calcium carbonate) at base of mountain ranges


Deserts have lots of mineral deposites (evaporated ocean once has all these minerals dissolved in it)

Sulfuric Acid

  • Discovered in 8th century by alchemist
  • Alchemy: trying to make gold out of cheaper materials
  • "Chemist"


Uses:

- Lead acid batteries (cars)

- Fertilizers

- Steel industry -> prevents rust corrosion

- Dried fruit production (hydrotropic)

TWO GASES LAB

Magnesium Carbonate and Acid: creates carbon dioxide


  • dense gas
  • Upright tube: gas can't escape (filled with carbon dioxide)
  • Inverted: gas escapes (filled with air)


Magnesium and Acid: creates hydrogen


  • flammable, light gas (ex: Hindenburg)
  • Upright: gas escapes (filled with air)
  • Inverted: Gas can't escape (filled with hydrogen)



"POP" = hydrogen is ignited and rushes out of tube


  • rubs against glass -> creates friction = sound



Errors:


  1. Not waiting 30 sec.
  2. Unstopper before inverting
  3. Break surface of water with tube
  4. Don't collect full tube of gas
  5. Air bubble in tube
  6. Stoppers not tight
  7. Not keeps tubes vertical

ACIDIFICATION OF WATER LAB

Phenol red indicator:

- red = basic

- clear = acidic


Phenol red changes color as you add carbon dioxide into water

- Turns into carbonic acid, lowering pH of water


Calcium tablet is more soluble in cup w/straw b/c:

- carbonic acid lowers pH and dissolves calcium faster


Errors:

  1. Don't bubble water long enough
  2. 2 cups don't have same amt. of water
  3. Lose water when using straw
  4. Put carbon dioxide into both cups


Ocean Acidification

  • Normal ocean pH is 8.1-8.4
  • Ocean's pH has decreased 0.1 (about 25%)
  • Lower ocean pH means sea animals with shells (made of calcium carbonate) can't make shell b/c:

- carbonic acid in water dissolves calcium carbonate