Monday's Science Quiz

4.9- Acidification Lab (two gases lab included)

Acid Rain

Gases dissolved in our atmosphere:

1) carbon dioxide

2) sulfur dioxide

3) hydrogen chloride

(these create an acidic solution)

carbonic acid --> dissolved carbon dioxide

sulfur dioxide --> "acid rain" (kill forests and pollute water such as rivers and lakes)

--> volcanoes

--> industrial solution

Limestone/Sinkholes

Limestone:

-porous (hold water)

-soft

-soluble in water (carbonic acid)

Florida sinkholes occur because...

-lots of limestone

-water underground (aquafer)

-once covered with ocean --> soft calcium deposits (dead animals)

Sulfuric Acid

-discovered in the 8th century by alchemist (sort of chemistry)

Uses:

-lead acid batteries (cars)

-fertilizers

-steel industry --> prevents rust corrosion

-dried fruit production (hydrotropic)

Two Gases Lab

Magnesium Carbonate and Acid:

-carbon dioxide is a dense gas that sinks

-in the upright test tube that is filled with carbon dioxide, the gas can't escape

-in the inverted test tube that is filled with air, the gas can escape

Magnesium and Acid:

-hydrogen is a light gas that rises

-in the upright test tube that is filled with air, gas can escape

-in the inverted test tube that is filled with hydrogen, the gas can't escape

The "Pop" Explained:

-gas is ignited and rushes out of test tube

-rubs against glass and causes friction (sound)

-flammable gas is escaping

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

-stoppers not tight

-not keeping test tubes vertical

Acidification Lab

-phenol red changes color as you add carbon dioxide into water

-the carbon dioxide 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:

-don't bubble water for long enough

-two cups don't have same amount of water

-lose water when using straw

-put carbon dioxide

Ocean Acidification

-normal ocean ph is 8.1-8.4

-ocean's ph has decreased about 0.1 ( about 25% down)

-lower ocean ph means sea animals with shells will not be able to make a shell (crabs,etc.)