End of Ch. 4 Quiz
4.9 Acid Rain
- hydrogen chloride
Carbonic Acid-dissolved CO2
Sulfur Dioxide (volcanoes, industrial pollution)-"acid rain"
- kill forest
- pollute water (rivers, lakes, and ponds)
What does calcium carbonate do to water?
- It makes it hard
Why can't the city publish a law that they can't distribute water with toxic substances?
- There is always a low level of toxic substances in public water, so if the law was passed, then there would be no water.
Why are large deposits of sodium chloride/potassium nitrate found near deserts?
- the desert was once an ocean
Limestone, Sinkholes & Sulfuric Acids
- porous (can hold a lot of water)
- a lot of it in Florida
- soluble in water (carbonic acid)
Florida sinkholes occur because:
- lots of limestone
- water underground in caves (aquifer)
- once covered with ocean --> soft calcium deposits (dead animals)
- discovered in 8th century by Alchemist (turns things into gold)
- alchemy--> chemistry
Sulfuric Acid uses:
- lead acid batteries (cars)
- steel industry --> prevents rust corrosion
- dried fruit production (hydrotropic)
Two Gases Lab
- In the upright test tube, which is filled with CO2, the dense gas sinks and cannot escape. The flame goes out right away.
- In the inverted test tube, which is now filled with air, the gas escapes. The flame stays lit.
- The light gas rises.
- In the upright test tube, which is filled with air, the gas escapes. It made a popping noise. The flame goes out.
- In the inverted test tube, which is filled with hydrogen, the gas cannot escape (why you wait 30 seconds. It made a popping noise.
- The gas is ignited and rushes out of test tube.
- Rubs against glass causes friction (sound)
Acidification of Water
- pH indicator
- red: basic
- clear: acidic
Phenol red in water:
- bright pink
with CO2 over water:
with CO2 in water
- phenol red changes color as you add CO2 into the water
- the CO2 turns into 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
- Normal Ocean pH is 8.1-8.4
- Ocean's pH has decreased 0.1 (about 25% down)
- Lower ocean pH means sea animals with shells will not be able to make a shell.