Sunday, April 27, 2014

Questions For You!


1.  Which compound contains the highest percentage of magnesium by mass?
(A)  MgNH4PO4
(B)  Mg(H2PO4)2
(C)  Mg2P4O7
(D)  Mg3(PO4)2

6. Which of the following is a weak electrolyte in aqueous solution?
(A) HF
(B) NaF
(C) HCl
(D) KCl

4. What is the molarity of sodium ions in a solution prepared by diluting 250. mL of 0.550 M Na2SO4 to 1.25 L?
(A) 0.110 M
(B) 0.138 M
(C) 0.220 M
(D) 0.275 M

Friday, April 4, 2014

And The 2014 Winners Are...

What happened to my room?

Each year the students make a molecular and brochure of their favorite molecule.  We then have a voting period over two days where current and former students as well as teachers vote on the models.  The votes are entered on a Google form accessed using any internet device.  Congratulations go out to all my students for producing these wonderful representations.

This years winners (by popular vote) are as follows...

First Place Period G and An Overall Winner
First Place Period C and An Overall Winner
In the dark

First Place Period B
First Place Period A
Other winners are as follows...
An Overall Winner Period G
Second Place (1) Period A 
Second Place (2) Period A
Second Place (1) Period B
Second Place (2) Period B
Second Place Period C

Second Place (1) Period G and An Overall Winner
Second Place (2) Period G
Second Place (3) Period G 

Tuesday, March 18, 2014

Balancing Redox Reactions

AP Chem:

Goto the following link for help with
Balancing Redox Reactions in Basic Solutions

Balancing Redox Reactions

For Extra Credit: 
Balance the following reaction in a basic solution
MnO4 -  +  C2O4 2-  ===>  MnO2  +  CO2

Balance the following reaction in an acid solution
Mn 2+  +  BiO3 -  ===>  MnO4 -  +  Bi 3+

Monday, March 10, 2014

Solubility Product(2)

Even More Extra Credit!

3. Silver salts are commonly used in photography as they darken on exposure to light.
What mass of AgCl is contained in 5.00 L of a saturated solution? Ksp = 1.6 E -10

4. Given the Ksp of Fe(OH)3 = 1.1 E -36, what is the [OH-] in a saturated solution?

Wednesday, March 5, 2014

Solubility Product (1)

Complete these questions for Extra Credit!

1. Lead based paints have been responsible for poisoning in many cases over years. A
common component is Lead II Carbonate, PbCO3. 535 Litres of a saturated solution of
this compound contains only 25.2 mg of solute in solution. Calculate the Ksp.

2. Strontium compounds are often burned in fireworks to produce a brilliant red colour.
Given that the Ksp of SrF2 is 7.8 x 10-10, what is the solubility of strontium fluoride?

Good Luck...

Saturday, March 1, 2014

H Chem % Yield Example

Honors Chem.

During an experiment nitrogen and hydrogen are used to make ammonia according to the reaction below.  If 2.68 moles of nitrogen reacted with hydrogen (unlimited amount) and produced 64.0 g of NH3, what is the percent yield of NH3?

N2 + 3H2 ↔ 2NH3