MHS Chemistry
Moles and Concentration

Before we begin, a note about names. Compounds that produce the hydroxide ion in solution are known as bases.  Compounds that produce hydrogen ions in solution are known as acids. Bases of this kind don't have special names, but the acids do. If the acid is of the form "hydrogen _____ate" then it would be called "_____ic acid" (example: hydrogen sulfate is also "sulfuric acid"). If the acid is a binary acid (just hydrogen and one other element), it is "hydro_____ic acid (example: HCl is "hydrochloric acid"). Got it? Good.

  1. How many grams of NaOH are needed to prepare 1.0 liters of a 1.5 M solution?

  2. How many grams of HNO3 are used to prepare 2.00 liters of a 1.00 M solution?

  3. How many grams of NaOH are required to prepare 5 liters of a 3 M solution?

  4. How many grams of NaOH are required to prepare 3.0 liters of a 2.0 M solution?

  5. How many grams of NaOH are required to prepare 1400 mL of a 3.00 M solution?

  6. How many grams of NaCl are required to prepare 500 mL of a 1.5 M solution?

  7. How many grams of KOH are required to prepare 1200 mL of a 0.50 M solution?

  8. How many grams of H2SO4 are required to prepare 900 mL of a 2.5 M solution?

  9. How many grams of magnesium sulfate are required to prepare 1.0 kiloliter of a 2.0 M solution?

  10. How many grams of HC2H3O2 are required to prepare 3.5 liters of a 1.5 M solution?
Calculate the molarity of the following solutions:
  1. 1.00 liter which contains 50.0 g NaOH.

  2. 5 liters which contains 126 g HNO3.

  3. 1400 mL which contains 120 g HC2H3O2.

  4. 500 mL which contains 63 g HN03.

  5. 1200 mL which contains 100 g sodium hydroxide.

  6. 800 mL which contains 196g H2SO4.

  7. 50 mL which contains 3.65 g HCl.

  8. 1.0 kiloliter which contains 56 kg KOH.

  9. 1500 ml. which comains 168 g KOH.

  10. 3 liters which contains 240 g NaOH.

Be careful with these! “Train-Tracks” will help a lot.
  1. How many liters of 2 M KOH can be prepared from 560 g of the solute?
  2. What volume of 1.5 M NaOH can be prepared from 960 g of the solute?
  3. If 16 liters of sucrose (C12H22O11) solution contain 2.736 kg of sucrose, what is the molarity of the solution?
  4. Calculate the number of molecules of sugar in 4.0 liters of 0.10 M solution. (Hint #1: Don’t forget Avogodro's number!  Hint #2: Do you need to know the formula for sugar?)
  5. Calculate the number of molecules of sugar in 500 mL of 3.00 M solution.
  6. Determine the number of moles of H2SO4 in 5000 mL of a 62% (by weight) solution of H2SO4 having a density of 1.52 g/mL.
  7. Calculate the molarity of a 29% (by weight) KOH solution having a density of 1.28 g/mL.
  8. How many mL of a 69% (by weight) HNO3 solution, having a density of 1.416 g/mL, are required to make 1000 mL of 2.00 M HN03 solution?
[Chapter 15 notes][MHS Chem page]