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InClass Problem Set #1
29 Aug 1996 Name ______________________________
1. Reagent grade aqueous ammonia is 14.5 M. Directions call for using 5 mL of 6M NH3 to clean each of your three sintered glass crucibles. How will you make the 6 M NH3?
A. How much 6 M NH3 should you make up? Why?
B. How many moles of NH3 will the solution in "A" contain?
C. How many mL of the 14.5 M NH3 solution will we need?
D. What is the procedure for making the 6 M NH3?
2. How many grams of AgNO3 are required to make 500 mL of 0.1M AgNO3?
A. How many moles of AgNO3 are in 500 mL of 0.1M AgNO3?
B. How many grams will these moles weigh? (The formula weight of AgNO3 is 169.837 grams/mole)
3. How much 0.1 M AgNO3 will be required to precipitate 0.2000 g of unknown chloride, if the sample is 60% chloride? (atomic wt. of Cl is 35.453)
A. How many grams of chloride are in the sample?
B. How many moles of chloride are in the sample?
C. How many moles of silver are required to precipitate the chloride? (Hint: Write the balanced chemical reaction between Ag+ and Cl-.)
D. How many mL of 0.1M AgNO3 are required to precipitate the chloride?