Introduction to Physical Science

4.9 to Acidification Lab Study Guide

Acid Rain

Acid rain is gases that have dissolved in our atmosphere.


What creates acidic solutions?

  • Co2
  • sulfur dioxide
  • hydrogen chloride



Carbon dioxide --> dissolved Co2

Sulfur dioxide --> "acid rain"


Sulfur dioxide can be found in:

  • volcanoes
  • industrial pollution


Acid rain has the capability to:

  • kill forests
  • pollute water (river, lakes, ponds)

Limestone/Sinkholes

Limestone characteristics:

  • porous (able to hold water)
  • soft
  • soluble in water (carbonic acid)


Florida Sinkholes occur because...

  • lots of limestone under under the surface of the earth
  • water underground (aquifers)
  • the surface was once covered with an ocean --> soft calcium deposits (dead animals)

Sulfuric Acid

Sulfuric acid was discovered in the eighth century by an Alchemist --> Alchemy (meaning chemistry)


Uses:


  • lead acid batteries (in cars)
  • fertilizers
  • steel industry --> prevents rust corrosion
  • dries fruit production (hydrotropic)

Two-Gases Experiment Post Lab

Magnesium Carbonate and Acid

Inverted Test Tube

  • Bottom (which is on the top) is filled with air
  • The gas escapes through the bottom


Up-right Test Tube

  • The test tube is filled with Co2
  • The gas cannot escape



*Co2 is a dense gas, so it sinks.

The "Pop"

Gas is ignited and rushes out of the test tube. It rubs against the glass and causes friction (sound).


In the inverted test tube, the flammable gas escapes.

Experimental Errors

  • not waiting thirty seconds
  • taking the stopper out before inverting the test tube
  • breaking the surface of water with the test tube
  • stoppers are not tight enough
  • not keeping the tubing vertical

Acidification of Water Post Lab

  • phenol red changes color as you add more Co2 to the water
  • the Co2 turns into carbonic acid lowering the pH of the water
  • calcium tablet is more soluble in a cup with a straw because the carbonic acid lowers the pH and dissolves the calcium faster

Ocean Acidification

The normal pH is 8.1-8.4


  • ocean's pH has decreased about 0.1 (about 24%)
  • lower ocean pH means that sea animals with shells will not be able to make a shell (i.e. crabs, shrimp, clams, etc.)

Experimental Errors

  • do not bubble the water long enough
  • both the cups do not have the same amount of water
  • lose water when using the straw
  • put the Co2 in both of the cups