IPS Quiz Study Guide 3/16/15

4.9 - Acidification Lab

4.9 Notes

The gases dissolved in our atmosphere are:
  • Carbon Dioxide
  • Sulfur Dioxide
  • Hydrogen Chloride

The gases above create an acidic solution.


Carbonic acid ---> dissolved carbon dioxide


Sulfur Dioxide ---> "acid rain"


  • Sulfur Dioxide is created by volcanoes and industrial pollution
  • Acid Rain kills forests and pollutes water

Page 91 BQ Answers

#32: Denver, because it is located at the base of the Rocky Mountains. Denver's water supply comes from the mountains and it picks up minerals on its way down the mountain.


#33: 0.05g per day; 18.25g per year


#34: There is always a low level of toxic substances in public water. There would be no water if the law was passed.


#35: Deserts were once oceans. Deserts get very little rain, so there was no rain to wash away/dissolve the solids at the surface.

Sinkholes and Limestone Notes

Limestone is soft, has holes (it is porous), and it holds water. However, limestone is also soluble in water because water has carbonic acid in it.


Sinkholes are common in Florida because there is lots of limestone underground here, and Florida was covered by ocean in the past.

Sulfuric Acid Notes

Sulfuric Acid was discovered in the 8th century by alchemists.


Alchemists --> alchemy

Alchemists --> chemists

Alchemists originally wanted to turn rocks into gold.


The uses of Sulfuric Acid are:

  • Lead acid batteries (for cars, etc.)
  • Fertilizers
  • Steel industry --> prevents rust corrosion
  • Dried fruit production (hydrotropic) (it pulls the water out of fruit)

Magnesium Carbonate and Acid Notes

If the test tube is upright, the carbon dioxide can't escape because it is a dense gas


If the test tube is inverted, the gas escapes because the air can't hold it in the test tube (carbon dioxide is denser than air)

Magnesium and Acid Notes

The gas created is Hydrogen (H)


If the test tube is upright, the gas can escape because it is less dense than air (it rises in air)


If the test tube is inverted, the gas can't escape because the air is holding up the light hydrogen in the test tube

"Pop" Notes

When the flame collides with the gas, the gas is ignited and it rushes out of the test tube.


The gas rubs against the glass of the test tube which causes friction (the "popping" sound)

Two Gases Lab: Experimental Errors

  • Not waiting 30 seconds before inserting the flame in the test tubes
  • If you take the stopper off of the test tubes before inverting them
  • If the test tubes break the surface of the water
  • If you don't collect a full test tube of gas
  • If there is an air bubble in the test tube to begin with
  • If the stoppers are not tight enough
  • If you don't keep the test tubes vertical during the flame test

FRAE Answers

#36a:
  • Test tube #1: 4 grams per 10 cubic centimeters/ 40 grams per 100 cubic centimeters
  • Test Tube #2: 8 grams per 10 cubic centimeters/ 80 grams per 100 cubic centimeters

#36b: The last two test tubes are saturated, which means every cubic centimeter of water in the last two test tubes are filled with the solid. This also means that both of their concentrations are the same, and most likely higher than 80 grams per 100 cubic centimeters.


#37a: Sodium Nitrate

#37b:

  • Test tube #1: All dissolved
  • Test tube #2: Will begin to precipitate
  • Test tube #3: Still saturated, but more precipitates
  • Test tube #4: Still saturated, but more precipitates


#38:

  • 15 degrees Celsius: 9.4 grams per 100 cubic centimeters (average the solubilities at 10 and 20 degrees)
  • 40 degrees Celsius: 24.4 grams per 100 cubic centimeters (double the solubility at 20 degrees)


#39: When the water evaporates and is boiled, the minerals in the water are left behind.


#40a:

  • Permanent: not soluble in water
  • Water color: soluble in water

#40b:

  • Permanent: Alcohol/oil based
  • Water color: Water based


#41a: The ink is soluble in hot water containing detergent or soap

#41b: No, because if it were to rain or if you were to spill a glass of cold water on your clothes, the color would bleed out of the clothes.


#42a: When there is more water for the gas to travel through, the more gas will dissolve.

#42b: No, because density is a characteristic property and it will always stay the same.


#43a: It gives the water more energy

#43b: You have increased the amount of the surface of solid touching the water

#43c: It gives the water more energy


#45: 0.0014 grams per 100 cubic centimeters

Acidification of Water Post Lab

Phenol red changes color as you add carbon dioxide into the water


The carbon dioxide turns to carbonic acid, lowering the pH of the water


The calcium tablet is more soluble in the cup with the straw because the carbonic acid lowers the pH and dissolves the calcium faster (more acidic water dissolves things faster)

Acidification of Water Lab: Experimental Errors

  • You did not put enough phenol red into the water
  • You do not bubble the water long enough
  • The 2 cups don't have the same amount of water

Ocean Acidification Notes

The ocean's pH has decreased by 0.1 on the pH scale (a 25% decrease)


A lower pH level will caused shelled-animals (shrimp, mollusks, etc.) to not be able to build a shell