Wednesday Night Homework

Wednesday Night Homework

By Kelly Moran

pg. 412 

9.) 

10.) This liquid should be classified as a solution because if no particles sank to the bottom then the molecules are mixed together which is what a solution is and also with a solution a light shines right through it unlike a colloid and in the example given the light shines through the substance revealing it is a solution. 

13.) a.) 2.11%

        b.) 0.009% 

14.) 1.) Oceans

       2.) Glaciers 

       3.) Water Vapor

       4.) Rivers

15.) Water is a renewable resource because water goes through a cycle. It is evaporated from the ocean and then fills up the clouds in the sky. Once clouds are completely full of water vapor, it rains and the water rolls down back into the ocean where the whole cycle repeats itself over again. We cannot gain or loose water because it just goes in this cycle which is why it's considered a renewable resource. 

16.) It possible that a molecule of water you drank was once swallowed by a dinosaur because water is a renewable resource and goes through a cycle. We cannot gain or loose water but simply recycle it. Water is basically always recycled which means the water you drink possible could have been drunk by a dinosaur millions of years ago. 

pg. 495

1.) To purify water means to separate water from it's bacteria or any other contamination that's not H2O. 

2.) Three techniques for purifying water include boiling, distillation, and disinfecting by using chlorine solution. 

3.) Bacteria, minerals, and any other non H2O molecules.  

4.) a.) There is way too much salt in seawater for it to be completely purified and used for drinking water.

     b.) To make seawater suitable for drinking it would need to be boiled. 

5.) 

6.) No water has been gained or lost over the millions of years on the earth. Water is a renewable resource on the earth that goes through a cycle. 

7.) A situation where this would be true is in Africa. In Africa they have plenty of water but none of the water is clean because they cannot afford factories to purify the water for drinking purposes. 

8.) If water evaporation stopped we would not have anymore water on the earth and the water cycle would completely end. Water would only be in the ocean and few lakes on the earth. 

11.) Aluminum hydroxide creates gels which clump certain molecules together to separate the colloids out of a liquid. 

12.) Calcium oxide is often added in the final steps of municipal water treatment to stop corrosion of the water pipes. 

13.) 1 ppm of Fluoride is added to the treated water because this is because it stops tooth decay. 

18.) Chlorinated drinking water is better than untreated water because you can get many diseases from the bacteria in it. 

19.) Chlorinated water is bad because it creates trihalomethane's which are bad for the human body.