Chemistry Problems (Balancing Equations)

pg 293 #47

a) Pb(NO3)2(aq) + NaOH(aq) => Pb(OH)2(s) + NaNo3(aq)


This is the balanced equation
Pb(NO3)2(aq) + 2NaOH(aq) => Pb(OH)2(s) + 2NaNo3(aq)

problems worked in class

sorry about it being late, i experienced many technical difficulties but finally got them up so here are the problem that we worked in class

Blabble.

Is there no Blog for tonight? If not, sorry for the un-needed post. If so, hope this reminds someone. Oh, and Dr. B., were you able to find my HW #8? I have HW #9 for you as well, and tried to turn it in at the end of school on Friday, but you had already left. Sorry for the inconvience.

another day in chemistry by chris mathews

today we started the class with some superb singing by michael and joe krebs to the popular tune of the lion king. While most of the audience thought it was great, there are always a few critics. On the matter of chemistry we discussed how to properly solve problems that will be on our test. the test will be either tuesday or hopefully thursday of next week. Remember to do your homework tonight which is the worksheet, and to SHOW YOUR WORK!!!! also support the wrestling team in their closing season as they go for state. good luck all with you homework, call kyle for any questions

chris mathews

1/20/10 Assignment Posting

We did an example problem for Colby and talked about the chart of ways stoichiometry problems can be asked. Two bits of homework tonight: HW7 is p. 321-322 #26-30, and HW8 are these four problems.

15. When heated, sodium bicarbonate, NaHCO₃, decomposes into sodium carbonate, Na₂CO₃, water, and carbon dioxide. If 5.00g of NaHCO₃ decomposes, what is the mass of the carbon dioxide produced?

16. A reaction between hydrazine, N₂H₄, and dinitrogen tetroxide, N₂O₄, has been used to launch rockets into space. The reaction produces nitrogen gas and water vapor.

a. Write a balanced chemical equation for this reaction.

b. What is the mole ratio of N₂O₄ to N₂?

c. How many moles of N₂ will be produced if 20,000 mol of N₂H₄ are used by a rocket?

d. How many grams of H₂O are made when 450. Kg of N₂O₄ are consumed?

17. Joseph Priestly is credited with the discovery of oxygen. He produced O₂ by heating mercury (II) oxide, HgO, to decompose it into its elements. How many moles of oxygen could Priestly have produced if he had decomposed 517.84 g of mercury oxide?

18. Iron (III) chloride, FeCl₃, can be made by the reaction of iron with chlorine gas. How much iron, in grams, will be needed to completely react with 58.0 g of Cl₂?

Have a good night.

Tuesday, January 19, 2010

Today we did a few review problems from the book on using mole-ratio conversions.
We also learned about Actual Yield and Theoretical Yield and how to find the % Yield
There was an equation to how to find the % Yield

Act. Y. - Actual Yield
Th. Y. - Theoretical Yield

(Act. Y./Th. Y.) * 100 = % Yield

We have been asigned to do homework problems 165-175 on pg. 890 so get them things done to turn in before the bell rings on time. Please and Thank You.

Goody Night Get Homework Done!!!!!!

1/19/10

Limiting Reactants: the reactant that limits the amount of the other reactant that can combine and the amount of product that can form in a chemical reaction
Excess Reactant: substance that is not used up completely in a reaction

When solving problems with chemical reactions and converting grams to moles/ moles to grams/ etc., set up a single equation so that you only round once.