Neutralization, Concentration, Molarity
Problem Set
1. Complete the neutralization reaction:
HClO4 + NaOH ![]()
2. If you add 300 mL 0.2 M HC2H3O2 to 650 mL water, what is the new concentration of the acetic acid solution?
3. 250 mL of 0.5 M HCl is reacted with 100 mL of 1.0 M Ca(OH)2. What is the limiting reagent?
4. How many moles of water are formed?
5. What is the molarity of the calcium hydroxide solution?
6. A 3 g sample of a soluble chloride is titrated with 52.60 mL of 0.2 M AgNO3. What is the percentage of chloride in the sample?
Stoichiometry and Concentration in ppm/ppb
Problem Set
1. What is the concentration of barium in ppm if 2.000 g of BaCl2 are dissloved in 6.00 L of water?
In our labs we formed AlCl3 to precipitate out the copper metal. The reaction was
3CuCl2 + 2Al
3Cu0 + 2AlCl3
2. If we added a solution of 25 ppm Al to a bucket of CuCl2, how many milligrams of copper would be formed?
3. Remember we formed CuCl2 by adding 6 M HCl to CuO. What’s the concentration of Cu2+ in ppm if 0.013 g of CuO is added to 0.5 L of 6 M HCl? (the density of 6 M HCl is 1.19 g/mL)
4. In the beginning of the copper experiment, we added NaOH to form Cu(OH)2 from a solution of Cu(NO3)2 . The Cu(NO3)2 was formed by dissolving the Cu0 in HNO3. If .0013 g of copper were dissolved in 100 mL of 12 M HNO3, how much 6 M NaOH is needed to neutralize the excess HNO3 before Cu(OH)2 could be formed?
5. What is the concentration in ppm of the Na+ ions in the solution? (assume the density of 12 M HNO3 is 1.30 g/mL and 1.05 g/mL for 6 M NaOH)
Practice Problems: If you can do these, you should get at least a B+ on the test!
a) If I mix 1 L of H2O with 125 mL of 6 M hydrochloric acid, what is the new concentration?
b) How many grams of sodium hydroxide do I need to make a 3 L bottle of 3.5 M solution?
c) If I have 10 mL of concentrated nitric acid(12 M), how much water do I need to add to make a 0.5 M solution?
d) How many mL of 2.0 M barium hydroxide is needed to neutralize 100 mL of 4.5 M sulfuric acid?
e) How many grams of CuSO4 are needed to form 45.0 g of CuSO4 * 5 H2O? (Assume unlimited water)
CuSO4 + 5 H2O
f)
If I add 27.4 g of calcium carbonate to 125 mL of 2.20 M hydrochloric acid, how many grams of carbon dioxide is given off? What is the limiting reagent? CaCO3 + HCl
CaCl2 + H2O CO2 (Not Balanced)
g)
If I mix 135 mL of 2.5 M potassium hydroxide with 238 mL of 0.6 M magnesium sulfate, how much magnesium hydroxide is formed? What is the limiting reagent? KOH + MgSO4
Mg(OH)2 + K2SO4 (Not balanced)