#14 and #15 on the homework due 12/19

14. 

2 H₃PO₄ + 3 Ca(OH)₂   à  Ca₃(PO₄)₂ + 6 H₂O

0.75 L x (6 mol/L) = 4.5 mol H₃PO₄

4.5 mol H₃PO₄ ∙ (6 mol H₂O/2 mol H₃PO₄) ∙ (18.0128 g H₂O/ 1 mol H₂O) = 243 g water

4.5 mol H₃PO₄ ∙ (1 mol Ca₃(PO₄)₂/2 mol H₃PO₄) ∙ (310 g Ca₃(PO₄)₂/1 mol Ca₃(PO₄)₂) = 698 g calcium phosphate

15. 

3 H₂SO₄ + 2 Al(OH)₃ à  Al₂(SO₄)₃ + 6 H₂O

0.250 L ∙ (2.5 mol Al(OH)₃ / 1 L) = 0.625 mol Al(OH)₃

0.625 mol Al(OH)₃ ∙ (3 mol H₂SO₄/2 mol Al(OH)₃) = 0.9375 mol H₂SO₄

18.0 = 0.9375/x    

X = 0.0521 L = 52.1 mL H₂SO₄

Writing Assignment 12/5

You have learned about two extremes of dealing with asbestos exposure.  You have watched how WR Grace executives withheld information from its workers regarding their exposure, and you have heard Mr. Barnett talk about all of the government regulation regarding asbestos in schools.  He obviously feels like these regulations are excessive.  Do you agree?  Explain your reasoning.

Limiting Reactant wksht

Mik'haela:  better later than never, right?

worksheet

Writing Topic

According to merriam-webster.com, the definition of symbiosis is:

sym·bi·o·sis

 noun \ˌsim-bē-ˈō-səs, -ˌbī-\

biology : the relationship between two different kinds of living things that live together and depend on each other

: a relationship between two people or groups that work with and depend on each other

Using the article as a basis for your discussion, explain how theoretical scientists and experimenters/observers are involved in a symbiotic relationship.

3 Additional Questions for HW due 11/14

Predict if a precipitate forms in each of the following.  If it does, complete and balance the equation using all appropriate reaction symbols.

1.   silver chloride +  sodium phosphate -->


2.   lead (II) chloride + aluminum sulfate -->


3.   zinc acetate + aluminum nitrate -->

ACT practice/writing assignment

Go to the following ACT practice question.  Then either write an email to tvoeller@fairfield.k12.mt.us or share a GoogleDoc (shared with me) explaining the reasons for your choice in a complete paragraph.

ACT chemistry question

Videos for Student Council students

Watch these in the order given:

Introduction (from Bozeman teacher)

Moles and conversions (Kahn Academy)

Mole conversions (from Bozeman teacher)

Writing assignment 10/14/14

Read the science selection from an ACT practice test question at Varsity Tutors.  Then use complete sentences (in an email to tvoeller@fairfield.k12.mt.us) to explain what answer you choose and what facts presented in the reading passage were used in arriving at that answer.  Three to five sentences should suffice.