Chemistry 139 – HW5
M. Stock
Name ____________________
1. Answer the following questions given this equation:
BF3
+
Li2SO3

B2(SO3)3
+
LiF
a. Balance the equation
b. Calculate molar masses for each molecule
c. If 37.29g BF3 is reacted with excess Li2SO3, how many grams of B2(SO3) could be
formed by the reaction?
d. If 189.4g of LiF are desired, how many grams of Li2SO3 are required (assuming
excess BF3)?
e. If 71.90g BF3 are reacted with 77.01g Li2SO3:
i. Which reactant will be the limiting reagent?
ii. How many grams of LiF can be made, given this limit?
iii. How many grams of the excess reagent will remain leftover?
Page 1
Chemistry 139 – HW5
M. Stock
Name ____________________
2. For each of the following, predict the products of the metathesis reactions by writing a
molecular equation, then write the net ionic equation for each reaction. Use the
solubility chart from class to predict precipitations. (or table 5.1 of text)
a. CaCl2 and Na3PO4
b. NaI and KBr
c. MgSO4 and Li2CO3
3. Give the molecular formula for and name the acid-counterparts of each of the following
polyatomic ions:
NO3-
SO42-
PO43-
CO32-
4. Predict the products and write a molecular equation for the following acid-base pairs
(be sure to balance each equation):
a. HCl + NaOH
b. H2SO4 + Al(OH)3
c. CH3CO2H + KOH
d. Sr(OH)2 + H3PO4
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Chemistry 139 – HW5
M. Stock
Name ____________________
5. Write a Net Ionic Equation for 5d.
6. Predict the products for the following gas forming reactions. Write a molecular equation
a. HCl + NaHCO3
b. H2SO4 + K2SO3
7. If BF3 from problem 1 came as a solution, how many mL of a 0.0343M BF3 solution
would be needed to produce .135 moles of B2(SO3)3 (assuming excess Li2SO3)?
8. A local well water supply is suspected to have an excessively high concentration of
soluble Barium salts. In order to analyze it, 25.00L of water was treated with excess
Na2CO3 to produce 68.25mg of the insoluble salt, BaCO3.
a. What is the Molarity of soluble Barium in the original water supply?
b. If barium is considered unsafe above 2mg/L, is this water dangerous?
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