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Tuesday, April 27, 2010

Tuesday April 27

SCH 3U
Finished Percent Yield Lab
Handed in one flow chart, data table and set of questions per group
Test Review
TEST TOMORROW

SNC 2D
Handed in yesterday's homework
Note on Converging and Diverging lenses
Practice Question 2 p. 261
Tomorrow - Lab (you have already made the flow chart for this)
Tonight - make predictions (do the drawings to locate the images) for the lab (SALT)
UNIT TEST FRIDAY APRIL 30 (OPTICS)

SNC 1PE
Planet Earth - Fresh Water Ecosystem
Unit Test May 3

4 comments:

Mohammed, Hassan, Khaled, and Sameer said...

Ms.Wiens, could you please help with this question?

A compound with a molar mass of 78.0g/mol is found to contain 92.29% carbon and 7.71% hydrogen, by mass. The molecular formula of the compound is.....

Lina said...
This comment has been removed by the author.
Lina said...

Ms. Wiens, for the Unit 2 Review questions in the textbook, how come there are only answers for questions 29-42?

MsWiens said...

There are 2 ways you can answer the molecular formula question:
1 - find empirical, then the empirical formula mass, then divide the molecular mass (given) by the empirical mass to get your multiplication factor to determine the molecular formula
2 - multiply the percents as decimals by the molar mass given for each element, then divide that mass by the molar mass of each element to find moles then find the lowest terms

The textbook manufacturer decides which questions have answers and which do not. If there is one you are unsure of, please post it.