Honors Chemistry s2

Honors Chemistry

Mr.Urig

Ch 15: Homework Packet

Ch 15 Essential Questions

What is Henry’s Law?

What are the parts of a solution?

How does water dissolve materials?

What factors affect solubility?

How does the amount of solute describe a solution?

How is solution concentration calculated?

How are solutions prepared?

What affect does adding a solute have on the properties of a solvent?

Use the following information to answer questions 1-5

One risk of deep-sea diving is a condition known as the bends, which can occur when divers surface too quickly from deep water. The cause of the bends is nitrogen (N2) gas coming out of solution in the diver’s blood and forming bubbles, or ‘boiling”. If the bubbles are large, they may block blood vessels, causing a tingling sensation, or they may even cut off the blood supply to vital organs. This condition may be fatal.

Henry’s law states that the solubility of a gas in a liquid is proportional to the partial pressure of the gas above the liquid. Given the date below, use Henry’s Law to explain how the bends may occur.

Henry’s Law Cg = kPg

Cg= solubility of the gas

Pg = partial pressure of the gas

k = proportionality constant

Partial Pressure at 1 atm / Solubility at 1 atm
N2 / 0.78 atm / 5.3 x 10-3 mol/L

1.  Calculate the Henry’s law proportionality constant for N2.

2.  At a depth of 100 m underwater, the water pressure is equal to 10 atm of pressure. What is the partial pressure of N2 at a pressure at 10 atm?

3.  What is the solubility of N2 at a pressure of 10 atm?

4.  Explain what happens to N2 as the diver descends?

Essays – Answer in complete sentences

5.  What is responsible for the “boiling” phenomenon that occurs when a diver surfaces too quickly?

6.  Water and ethanol are miscible in all proportions, whereas oil and water are

immiscible. Explain this statement.

7.  Why is antifreeze added to a car’s cooling system?

State if solubility increases, decreases or stays the same

1.  _____ Raising the temperature of a liquid solution when the solute is a gas.

2.  _____ Raising the temperature of a liquid solution, if the temperature remains constant when a solid solute is mixed with the solvent.

3.  _____ Raising the temperature of a liquid solution, if the temperature rises when a solid solute is mixed with the solvent.

4.  _____ Raising the temperature of a liquid solution, if the temperature drops when a solid solute is mixed with the solvent.

5.  _____ Increasing the pressure above a liquid solution when the solute is a gas.

6.  Describe the effect of surface area, stirring, and temperature on solubility of a solid solute in a liquid solvent.

Solve the following problems – show all work

7.  What is the molarity of the solution formed by mixing 0.20 mol of sodium hydroxide (NaOH) with enough water to make 150 mL of solution?

8.  How much potassium bromide (KBr), in grams, should be added to water to prepare 0.50 L of solution with a molarity of 0.125 M?

9.  What is the molality of an alloy containing 0.03 g of silver and 4.75 g of iron?

10.  The molality of a solution of chlorine and water is 0.0362 m. This solution contains 3500 g of water. How much chlorine, in grams, was used to prepare this solution?

11.  A gas mixture contains 26.3 g of nitric oxide (NO) and 36.2 g of oxygen gas. What is the mole fraction of nitric oxide?

12.  A gas mixture contains the following gases with the mole fractions indicated: N2O4 (0.221), CH4 (0.10), O2 (0.210), and N2 (0.463). The mixture also contains CO. What is the mole fraction of CO in this mixture?

Answer each of the following questions in the space provided.

13.  Describe how a chemist can accurately prepare a solution of precise molarity?

14.  What is the molarity of the solution produces when 145 g of sodium chloride (NaCl) is dissolved in sufficient water to prepare 2.75 L of solution?

1.  How many grams of potassium chloride (KCl) are needed to prepare 0.750 L of a 1.50 M solution of potassium chloride in water?

2.  What is the molarity of the solution produced when 85.6 g of hydrochloric acid (HCl) is dissolved in sufficient water to prepare 0.385 L of solution?

3.  To produce 3.00 L of a 1.90 M solution of sodium hydroxide (NaOH), how many grams of sodium hydroxide must be dissolved?

4.  If 8.77 g of potassium iodide (KI) are dissolved in sufficient water to make 4.75 L of solution, what is the molarity of the solution?

5.  In order to prepare 2.00 L of a 3.00 M solution of ferric chloride (FeCl3), how many grams of ferric chloride must be used?

6.  What is the molarity of the solution produced when 14.1 g of ammonia (NH3) is dissolved in sufficient water to prepare 0.100 L of solution?

7.  To prepare 10.5 L of a 2.50 M solution of potassium hydroxide (KOH), how many grams of potassium hydroxide must be used?

8.  What is the molality of a solution containing 75.2 g of silver perchlorate (AgClO4) dissolved in 885 g of benzene?

9.  What is the molality of a solid solution containing 0.125 g of chromium and 81.3 g of iron?

10.  If 18.6 g of methanol is used to dissolve 2.68 f of Hg(CN)2, what is the molality of the solution?

11.  What is the molality of solid solder wire if it is made from 68.7 g of lead dissolved in 117 g of tin?

12.  What is the molality of a solution made by dissolving 8.11 g of potassium sulfide (K2S) in 47.6 g of ethanol?

13.  What is the molality of a solution containing 1330 g of methanol (CH3OH) and 16.6 g of sodium bromide (NaBr)?

14.  What is the molality of a solution containing 867 g of aluminum and 14.9 g of copper?

15.  Calculate the molality of a solution produced using 15.2 g of calcium chloride (CaCl2) and 345 g of methanol (CH3OH).

16.  In order to prepare a 0.523 m aqueous solution of potassium iodide (KI), how many grams of potassium iodide must be added to 2.00 kg of water?

17.  A gas mixture contains 45.6 g of carbon monoxide and 899 g of carbon dioxide. What is the mole fraction of carbon monoxide?

18.  A gas mixture contains the following gases with the mole fractions indicated: CH3 (0.510), C2H6 (0.431), C3H8 (0.011), and C4H10 (0.013). The mixture also contains the gas acetylene (C2H2). What is the mole fraction of acetylene?

19.  What is the mole fraction of oxygen in a mixture that contains 66.8 g of oxygen, 44.1 g of nitrogen, and 21.5 g of hydrogen?

20.  What is the mole fraction of xenon in a mixture that contains 0.584 g of xenon, 86.40 g of argon, and 3.62 g of neon?

21.  A gas mixture contains the following gases with the mole fractions indicated: NH3 (0.214), Cl2 (0.452), NH2Cl (0.118), and N2 (0.175). The mixture also contains HCl gas. What is the mole fraction of HCl gas?

22.  A gas mixture contains the following gases with the mole fractions indicated: H2 (0.164), H2 (0.278), O2 (0.455), and CO2 (0.101). The mixture also contains carbon monoxide. What is the mole fraction of carbon monoxide?

23.  A gas mixture contains 70.25 g of steam, 1.470 g of hydrogen, and 6.58 g of nitrogen. What is the mole fraction of steam?

I.  How many grams are needed to prepare the following solutions?

1.  3.0 L and 2.0 M NaOH

2.  500. mL and 1.5 M CaCl

3.  900 mL and 2.5 M H2SO4

4.  3.5 L and 1.5 M HC2H3O2

5.  1400. mL and 3.00 M NaOH

6.  1200 mL and 0.50 M KOH

7.  1.0 kL and 2.0 M MgSO4

II.  Calculate the molarity of the following solutions – show all work

8.  1.00 L and 50. g NaOH

9.  5 L and 126 g HNO3

10.  1400. mL and 120.g of HC2H3O2

11.  500. mL and 63 g of HNO3

12.  1200. mL and 100.g of NaOH

13.  800 mL and 196 g H2SO4

14.  50 mL and 3.65 g HCl

15.  1 kL and 56 g KOH

16.  3 L and 240.g NaOH

17.  560. g of KOH are available to prepare a 2.0 M solution. How many liters of solution can be made?

18.  960. g of NaOH are used to make a 1.5 M solution. What volume of solution is made?

19.  If 16 L of sucrose (C12H22O11) solution contain 2.736 kg of sucrose, what is the molarity of the solution?

Perform the following calculations to find the molarity of the following solutions – Show all work

1.  300. grams of CaCO3 dissolved in 1500. mL of solution

2.  160. g of NaOH dissolved in 500. mL of solution.

3.  42. g of H2SO4 dissolved to make 0.25 liters of solution.

4.  5.6 L of CO2 gas (at STP) dissolved in 2500. mL of solution.

Solve the following problems – show all work

5.  How many moles of NaOH are in 600. mL of 3.0 M NaOH solution?

6.  How many liters of 3.0 M NaOH solution contain 0.15 moles of NaOH?

7.  What volume of a 0.64 M H2SO4 solution contains 2.3 moles of H2SO4?

8.  How many moles of CaCO3 are found in 3.5 liters of a 2.5 M CaCO3 solution?

9.  How many grams of CaCO3 are found in 600. mL of a 1.20 M CaCO3 solution?

10.  How many liters of 1.0 M NaOH solution contains 3.0 grams of NaOH?

Solve the following dilution problems

11.  If 50 mL of 3.0 M HCl solution is diluted to 150 mL, what is the molarity of the dilute solution?

12.  If 80. mL of 12.0 M H2SO4 is diluted to 200 mL of solution, what is the new molarity?

Colligative Property Problems

1. What is the boiling point elevation when 11.4 g of ammonia (NH3) is dissolved in 200. g of water? Kb for water is 0.52 C°/ m.

2. How many grams of benzoic acid (C7H6O2) must be dissolved in 78.1 g of ethanol to raise the boiling point by 4.00 C°? Kb for ethanol is 1.20 C°/m.

3. If 67.7 g of urea (CH4N2O) is dissolved in 833 g of chloroform, what is the elevation in the boiling point? Kb for chloroform is 3.85 C°/m.

4. How many grams of camphor (C10H16O) are needed to raise the boiling point of 43.5 g of benzene by 2.10°C? Kb for benzene is 2.67 C°/m.

5. If 1800 g of ethylene glycol (C2H6O2) is added to 1900 g of water, what is the elevation in the boiling point? Kb for water is 0.52 C°/m.

6. If the boiling point o 69.6 g of carbon tetrachloride must be raised by 10.2°C, how many grams of pyridine (C5H5N) must be dissolved in the carbon tetrachloride? Kb for carbon tetrachloride is 5.02 C°/m.

7. What is the boiling point elevation when 31.5 g of menthol (C10H20O) is dissolved in 258 g of acetic acid? Kb for acetic acid is 2.93 C°/m.

8. How much will the boiling point of 25.0 g of acetic acid be raised if 2.69 g of picolinic acid (C6H5N2) is dissolved in the acetic acid? Kb for acetic acid is 2.93 C°/m.

9. Styrene glycol (C8H10O2) is a plasticizer. How many grams of styrene glycol must be dissolve in 98.7 g of benzene to raise the boiling point by 8.57°C? Kb for benzene is 2.67 C°/m.

10. What is the boiling point elevation when 43.5 g of the dye magenta I (C20H20ClN3) is dissolved in 1650 g of ethanol? Kb for ethanol is 1.20 C°/m.

11.How many grams of silver would have to be dissolve in 1120 g of ethanol to lower the freezing point by 0.25 C°? Kf for ethanol is 1.99 C°/m.

12. What is the freezing point depression when 85.3 g of oxygen is dissolved in 1500 g of water? Kf for water it 1.86 C°/m.

13. Ethylene glycol (C2H6O2) is the principal ingredient in antifreeze. How many grams of ethylene glycol will be needed to lower the freezing point of 2100 g of water by 20 C°? Kf for water is 1.86 C°/m.

14. How many grams of diphenyl (C12H10) must be dissolve in 655 g of benzene to lower the freezing point by 3.20 C°? Kf for benzene is 5.12 C°/m.

15. Perylene (C20H12) is a constituent of coal tar. How many grams of perylene must be dissolve in 66.9 g of chloroform in order to lower the freezing point by 2.75 C°? Kf for chloroform is 4.68 C°/m.

16. How much will the freezing point of 1050 g of benzene be lowered if 31.1 g of orcinol (C7H8O2) is dissolved in the benzene? Kf for benzene is 5.12 C°/m.

17. What will be the freezing point depression if 42.0 g of ibuprofen (C13H18O2) is dissolved in 975 g of naphthalene? Kf for naphthalene is 7.00 C°/m.

18. If 13.4 g of medication scopolamine (C17H21NO4) is dissolved in 50.3 g of water, how much will the freezing point be lowered? Kf for water is 1.86 C°/m.

19. How many grams of pyrazole (C3H4N2) must be added to 451 g of benzene to lower the freezing point by 5.00°C? Kf for benzene is 5.12 C°/m.

20. If you lower the freezing point of 16.8 g of chloroform by 2.50°C by using chlorine gas, how many grams of chlorine gas must be dissolved in the chloroform? Kf for chloroform is 4.68 C°/m.