Acidification Quiz Study Guide

Test: 3/16/15

Acid Rain

Gases dissolved in our atmosphere:


-CO2

-Sulfur dioxide

-Hydrogen chloride

All create an acidic solution


-Carbonic acid--> dissolved CO2


Sulfur dioxide--> "acid rain"

-Volcanoes

-Industrial pollution

(Acid rain kills forests, pollute water (river, lake, pond))

Limestone/Sinkholes

Limestone

  • Porous (holds water)
  • Soft
  • Soluble in water (carbonic acid)

Florida sinkholes occur because:

  • lots of limestone
  • water underground (aquifer)
  • once covered with ocean --> soft calcium deposits (dead animals)

Sulfuric Acid

-discovered in 8th Century by Alchemist --> Alchemy "Chemistry"


Uses

  • Lead acid batteries (cars)
  • Fertilizers
  • Steel industry --> prevents rust corrosion
  • Dried fruit production (hydrotropic)

Two Gases Post-Lab

Magnesium Carbonate and Acid

CO2 is a dense gas, so it sinks

Upright test tube is filled with CO2--> gas can't escape

Inverted test tube is filled with air--> gas escapes


Magnesium and Acid

Hydrogen (H) is a light gas, so it rises

Upright test is filled with air--> gas escapes

Inverted test tube is filled with hydrogen --> the gas cannot escape


"Pop"

  • Gas is ignited and rushes out of test tube. Rubs against glass and causes friction (sound)


Experimental Errors

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

Phenol Red

-pH indicator

-red: basic

-clear: acidic

Acidification Post-Lab

-Phenol red changes color as you add CO2 into the water

-CO2 turns to carbonic acid lowering the pH of the water


-Calcium tablet is more soluble in cup with straw because the carbonic acid lowers pH and dissolves calcium faster


Experimental Errors

  • Not enough phenol red
  • Don't bubble water long enough
  • 2 cups don't have same amount of water (put CO2 into both cups)
  • Lose water when using straw


Ocean Acidification

Ocean's pH has decreased 0.1

Normal ocean pH in which fish and other animals are healthy: 8.0-8.4

About 25% drop in pH

Lower pH will cause shelled animals (shrimp, mollusks, etc.)