pH and pOH

To determine the pH of a solution or the pOH of a solution, you have to know the {H+} concentration or the {OH-} concentration. In order to know how to do this we have to memorize this square

https://strehl-chemistry.wikispaces.com/file/view/Strehl_Square.png/111087617/Strehl_Square.png

An example question one might see includes:
What is the pH of a solution that is 12.5 M HCL?
pH= -log{H+}
     = -log{12.5}
     = -1.097

Acid and Bases

Most of us have learned about acids and bases. We have learned that acids and bases have distinct physical properties. Acids taste sour and feel sticky while bases taste bitter and feel slippery. Most of us also know that acids turn litmus paper red with a pH of 0-6.9 while bases turn litmus paper blue and have a pH of 7.1-14. But there are also many different definitions of acids and bases. In the Arrhenius definition of and acid and a base, acids produce hydrogen ions in a solution while bases produce hydroxide ions in a solution. In the Bronsted-Lowery definition acids donate a proton while bases accept a proton.

Night Before the Unit Test

I feel fairly confident on my abilities to do well on this test. After looking back on my quiz I realized I made mistakes that could have been avoided if I had read the questions more closely. For this test I looked over my last quiz, did all of the online worksheets, read the book, and watched some videos. some links that helped me included:
Video 1
Video 2
Video 3
 Molarity Practice Problems
What is a Solution?
Saturated, Supersaturated, and Unsaturated

Quizzes

After getting our quizzes back i was very disappointed with my score. When looking back over it i realized i had made careless mistakes. I felt like i understood the things we were learning in class but once i got to the quiz i learned that there were a couple things i definitely need to review before the unit test.

Here are some pictures of concepts that might be helpful for the unit test:

What is molarity:

http://study.com/cimages/multimages/16/equation-molarity.jpg

Steps to finding molarity:

http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/section_12/98b90bf53c6948bc1dbe6873793741b9.jpg


http://www.chem.sc.edu/goode/oldC112web/ch12nf/img057.JPG

Mass percentage

Mass percentage is = the mass of A in the solution/ the total mass of the solution X 100.

When doing these kinds of problems you have to be aware that substance A is your solute while your solution is the mass of the solute + the mass of the solvent. An example question of this is: What mass of water must be added to 425 grams of formaldehyde to prepare 40.0% (by mass) solution of formaldehyde? 

To solve this problem you would set up the equation like this: .400= 425g./(425g + Xg) this then becomes 170+ .400X=425 this means that X would equal 638g H2O 

Another example:

http://image.slidesharecdn.com/ch3-140221122959-phpapp01/95/ch-34-law-of-definite-proportions-11-12-8-638.jpg?cb=1392985833

Solution Composition

Solutions are defined as a mixture with a solute and solvent. The solvent is the substance that is there in the largest quantity for example in Kool-Aid the solvent is the water used to make it. Then the solute is what you put into the solvent. In the Kool-Aid example the solute is the sugar. You can define a solution in three categories: unsaturated, saturated, and supersaturated. The picture below explains these three concepts:

http://i.imgur.com/UoOSZuN.jpg