University:
Eastern Kentucky University
Course:
CHE 111 | General Chemistry
Academic year:

2020
Views:

358

Pages:

2
Author:

Nesbyenvkk

Molarity Problems Worksheet M = _n_ V - n= # moles - V must be in liters (change if necessary) - Use M or mol/L as unit for molarity 1. What is the molarity of a 0.30 liter solution containing 0.50 moles of NaCl? 2. Calculate the molarity of 0.289 moles of FeCl3 dissolved in 120 ml of solution? 3. If a 0.075 liter solution contains 0.0877 moles of CuCO4, what is the molarity? 4. How many moles of NaCl are present in 600. ml a 1.55 M NaCl solution? 5. How many moles of H2SO4 are present in 1.63 liters of a 0.954 M solution? 6. How many liters of solution are needed to make a 1.66 M solution containing 2.11 moles of KMnO4? 7. What volume of a 0.25 M solution can be made using 0.55 moles of Ca(OH) 2? For all of the problems below you will need to do a mole-mass conversion. Each problem will involve two steps. 8. What is the molarity in 650. ml of solution containing 63 grams of NaCl? 9. How many grams of Ca(OH)2 are needed to produce 500. ml of 1.66 M Ca(OH)2 solution? 10. What volume of a 0.88 M solution can be made using 130. grams of FeCl2 ? Answers: (done quickly; there may be errors) 1. 1.7 M 2. 2.41 M 3. 1.2 M 4. 0.930 moles 5. 1.56 moles 6. 1.27 L 7. 2.2 L 8. 1.7 M 9. 61.5 grams 10. 1.2 L Dilution Problems Worksheet 1. How do you prepare a 250.-ml of a 2.35 M HF dilution from a 15.0 M stock solution? 2. If 455-ml of 6.0 M HNO3 is used to make a 2.5 L dilution, what is the molarity of the dilution? 3. If 65.5 ml of HCl stock solution is used to make 450.-ml of a 0.675 M HCl dilution, what is the molarity of the stock solution? 4. How do you prepare 500.-ml of a 1.77 M H2SO4 dilution from an 18.0 M H2SO4 stock solution? Answers: 1. 39.2-ml (Put in paragraph form) 2. 1.1 M 3. 4.64 M 4. 49.2-ml Take 49.2-ml of 18.0 M H2SO4 stock solution and pour it into a 500-ml volumetric flask. Fill to the 500-ml line with distilled water to make 1.77M H2SO4 solution. Extra Molarity Problems for Practice 1. How many moles of LiF would be required to produce a 2.5 M solution with a volume of 1.5 L? 2. How many moles of Sr(NO3)2 would be used in the preparation of 2.50 L of a 3.5 M solution? 3. What is the molarity of a 500-ml solution containing 249 g of KI? 4. How many grams of CaCl2 would be required to produce a 3.5 M solution with a volume of 2.0 L? Answers: 1. 3.75 M 2. 8.75 M 3. 3.00 M 4. 7.8 x 102g