Water Flashcards
What do you get from hard water?
Scum and scale
How can you try get a nice lather instead of scum?
Use a soapless detergent
What is scale? Why is it bad?
Mostly calcium carbonate on inside of pipes when heated
Blocks pipes and heating systems - less efficient
What is the hardness caused by?
Ca2+ and Mg2+ ions
What are the benefits of hard water?
Calcium ions are good for healthy teeth and bones
Less risk of heart disease - minerals in water
What is temporary hardness caused by?
Hydrocarbonate ion - HCO 3-
How can temporary hardness be removed?
Boiling - calcium hydrocarbonate decomposes to calcium carbonate - insoluble
What is permanent hardness caused by?
Dissolved calcium sulfate
How can hard water be softened?
Add washing soda - sodium carbonate
How can hard water be removed?
Run it through ion exchange columns containing sodium ions and exchanges them calcium or magnesium
What could you use to compare hardness of water samples?
Titration
What is the merged of titration?
- fill burette of soap solution
- add water sample to flask
- add soap solution and shake flask
- repeat until a good lasting lather - bubbles cover for 30 seconds
- record how much soap was need and test over samples
The less soap needed in titration the…?
Less hard the water is
Where does water from resivoirs go to be treated?
-passes through mesh, chemicals added to make microbes stuck together and fall to bottom, filtered through gravel beds to remove all solids, water is chlorinated to kill of any harmful microbes
What do water filters contains?
Carbon and silver to remove chlorine taste and kill bugs
