Wednesday, April 29, 2009

4.3 & 4.4: Acids, Bases, and Alloys

Our final chapter of the chemistry looks first at acids and bases.

How are they related?
What makes a solution an acid? What makes a base?

And then we focus on alloys.

Why are we talking about metals during a solutions chapter?
How did the copper penny turn "silver"? "gold"?

All of this culminates on firday with presentations for Contract 26.

4 comments:

kristin said...

Alloys are solid solutions. An alloy is a mixture of one metal and one or more other elements. Teh reason the penny turned silver is because the base in the flask dissolved the zinc and coated the copper on the penny. Itt turnedgold after beacause the flame melted the zinc and copper together to make brass.

Phoebe-or-Phoebster said...

ACIDS AND BASES

How are they related?
*Acids and bases are related because they can neutralize each other. ex: antacid and stomach acids
They also usually only act on themselves in water.
Acid +base=water
What makes a solution an acid? A base?
*an acid has a pH under 7 and they are able to donate protons
*a base has a pH above 7 and they are able to accept protons

ALLOYS

Why are we talking about metals in a solution chapter?
*most metals are alloys which are just combinations of metals
How did the copper penny turn gold/silver?
*the base in the flask on your desk made the zinc dissolve and coat the penny in it. Then when you put a flame on it the zinc and the copper melted together to form brass.

becccccccccca. said...

We are talking about alloys because they are technically solid solutions.

The penny was coated in a silver metal that i can't remember;
and then when you heated it the silver metal and the metal underneath melted together forming an alloy.

-becccccccccca. :)

Laruen said...

1. acids and bases are related because they nuetralize each other.
2. solution an acid is um.... diff. charachtrasitics like taste and burn. Also you can use one of those litmus paper thingys to test it.
3. Bases are the same =)
4. Soultions put together make up a object when hardened. SOMETIMES!
5. The chemical and zinc on the penny reacted to each other causing the penny to get "stripped" and leaving just the silver part of the penny left over. When you put heat over it the heat reacted with the chemical making a physical change. It didnt turn back because there was no zinc! Im so smart!