1. Nickel has a face-centered-cubic unit cell. The density of nickel is 6.84 g/cm 3. Calculate the atomic radius of nickel.

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1 ADDITIONAL PRACTICE ON UNIT CELLS 1. Nickel has a face-centered-cubic unit cell. The density of nickel is 6.84 g/cm 3. Calculate the atomic radius of nickel. 2. Tungsten metal exists in a body-centered-cubic structure. The atomic radius of tungsten is nm. Calculate the density of solid tungsten. 3. The radius of gold atoms is nm and the density of gold is g/cm 3. Determine if gold has a face-centered-cubic structure or a body-centered-cubic structure. 4. Unit cells for xenon fluoride and nickel arsenide are shown below. Determine their empirical formulas. (a) (b) 5. Unit cells for calcium chloride and lithium oxide are shown below. Determine their empirical formulas. 6. Draw pictures on the atomic level of three layers of atoms that are cubic closest packing and hexagonal closest packing.

2 *7. The unit cell for sodium chloride is shown below. where the chloride ions create a face centered cubic unit cell pattern, and the sodium ions occupy the octahedral holes in the unit cell. An ionic substance will crystallize in this pattern with the smaller ions occupying the octahedral holes as long as the smaller ions are large enough to prevent the larger ions from touching each other, and therefore repelling. How large must the radii of the smaller ions be, in relationship to the larger ions, in order for the ionic substance to crystallize in this pattern? ADDITIONAL PRACTICE FOR CONCENTRATION UNITS 1. Calculate the mass percent of solute for each of the following solutions. (a) 31.0 grams of potassium chloride dissolved in grams of water. (b) 4.5 grams of toluene dissolved in 29.0 grams of benzene. (c) 5.5 grams of sodium bromide dissolved to make 78.2 grams of solution. (d) 22.0 grams of glucose (C 6 H 12 O 6 ) dissolved in 115 ml of ethanol. The density of ethanol is g/ml. 2. Calculate the mole fraction of solute for each of the following solutions. (a) 38.4 grams of lithium nitrate dissolved in 175 grams of water. (b) 33.0 g of sodium phosphate dissolved in 253 grams of water. (c) 9.95 grams of anthracene (C 12 H 10 ) dissolved in 100. ml of hexane (C 6 H 14 ). The density of hexane is g/ml. 3. Calculate the molarity for each of the following solutions. (a) 10.4 grams of calcium chloride dissolved in enough water to make 220. ml of solution. (b) 6.57 grams of methanol (CH 3 OH) dissolved in enough water to make 150. ml of solution. (c) 7.82 grams of naphthalene (C 10 H 8 ) dissolved in enough benzene to make 85.2 ml of solution. (d) 143 grams of barium chloride dihydrate dissolved in enough water to make 750. ml of solution.

3 4. Calculate the molality for each of the following solutions. (a) 26.2 grams of magnesium chloride dissolved in 425 grams of water. (b) 14.3 grams of sucrose (C 12 H 22 O 11 ) dissolved in 676 grams of water. (c) 7.82 grams of naphthalene (C 10 H 8 ) dissolved in 85.0 ml of pentane (C 5 H 12 ). The density of pentane is g/ml. 5. A solution is prepared by dissolving g of magnesium chloride in enough water to make ml of solution. Calculate the (a) molarity of magnesium chloride (b) molarity of each ion present in the solution 6. A solution is prepared by dissolving g of aluminum iodide in enough water to make ml of solution. Calculate the (a) molarity of the aluminum iodide (b) molarity of each ion present in the solution 7. A solution is prepared by dissolving 12.5 g of iron (II) sulfate in 95.0 g of water. The volume of the solution is ml. Fill out the unshaded regions in the table below, then calculate the following concentration units Mass (g) Quantity of Matter (mol) Volume (ml) Solute Solvent Solution (total) (a) mass percent of iron (II) sulfate (c) molality of iron (II) sulfate (b) molarity of iron (II) sulfate (d) mole fraction of iron (II) sulfate 8. A solution is prepared by dissolving 15.0 g of sodium nitrate in enough water to make the solution s volume ml. The solution s density was determined to be 1.12 g/ml. Fill out the table below, then calculate the following concentration units Mass (g) Quantity of Matter (mol) Volume (ml) Solute Solvent Solution (total) (a) mass percent of sodium nitrate (c) molality of sodium nitrate (b) molarity of sodium nitrate (d) mole fraction of sodium nitrate

4 9. Concentrated hydrochloric acid is 37.0% HCl by mass and has a solution density of 1.19 g/ml. Fill out the unshaded regions of the table below, then calculate the following concentration units Mass (g) Quantity of Matter (mol) Volume (ml) Solute Solvent Solution (total) (a) molarity of HCl (c) mole fraction of HCl (b) molality of HCl ADDITIONAL PRACTICE FOR COLLIATIVE PROPERTIES 1. Calculate the equilibrium vapor pressures for each of the following solutions. (a) 396 grams of sucrose (C 12 H 22 O 11 ) dissolved in 624 grams of water at 30ºC, if the equilibrium vapor pressure of pure water at 30ºC is 31.8 torr. (b) 24.6 grams of camphor (C 10 H 16 O) dissolved in 98.5 grams of benzene at 26.1ºC, if the equilibrium vapor pressure of pure benzene at 26.1ºC is torr. (c) 396 grams of sodium chloride dissolved in 315 grams of water at 25ºC, if the equilibrium vapor pressure of pure water at 25ºC is 23.8 torr. 2. Calculate the equilibrium vapor pressures for each of the following solutions. (a) 40.0 grams of methanol (CH 3 OH) dissolved in 60.0 grams of acetone (C 3 H 6 O) at 20ºC, if the equilibrium vapor pressure of pure methanol at 20ºC is 96.9 torr and the equilibrium vapor pressure of pure acetone at 20ºC is torr. (b) 75.5 milliliters of ethanol (C 2 H 5 OH, density = g/ml) dissolved in 24.5 milliliters of water (density = 1.00 g/ml) at 20ºC, if the equilibrium vapor pressure of pure ethanol at 20ºC is 43.6 torr and the equilibrium vapor pressure of pure water at 20ºC is 17.5 torr. 3. Calculate the boiling points for each of the following solutions. (a) 125 grams of calcium bromide dissolved in 675 grams of water. (b) 16.8 grams of elemental sulfur (S 8 ) dissolved in 90.0 grams of carbon tetrachloride. 4. Calculate the freezing points for each of the following solutions. (a) 40.7 grams of lithium nitrate dissolved in 245 grams of water. (b) 9.85 grams of elemental iodine dissolved in 30.0 grams of benzene. 5. Calculate the osmotic pressures for each of the following solutions. (a) water from the Dead Sea, 5.8 M sodium chloride, at 19ºC (b) 31.2 grams of potassium sulfate dissolved to make 500. ml of solution at 22ºC

5 6. Calculate the molar mass of each solute based upon the given experimental data. (a) grams of an organic nonelectrolyte dissolved in 25.6 grams of carbon disulfide, and the boiling point of the solution is found to be 48.3ºC (b) grams of a nonelectrolyte dissolved in 75.6 grams of water, and the freezing point of the solution is found to be -5.58ºC (c) 1.22 grams of an organic nonelectrolyte dissolved in water to make 262 ml of solution, and the osmotic pressure of the solution is found to be 30.3 torr at 35ºC. PRACTICE UNIT CELL ANSWERS cm g/ml 3. face-centered cubic 4. (a) XeF 2 (c) NiAs 5. (a) CaCl 2 (c) Li 2 O 6. cubic closest packing hexagonal closest packing *7. > 41.4% of the larger ions

6 PRACTICE CONCENTRATION UNITS ANSWERS 1. (a) 16.9% KCl (b) 13% toluene (c) 7.0% NaBr (d) 19.5% glucose 2. (a) (b) (c) (a) M (b) 1.37 M (c) M (d) M 4. (a) m (b) m (c) 1.15 m C 10 H 8 5. (a) M (b) M Mg 2+, M Cl - 6. (a) M AlI 3 (b) M Al 3+, M I - 7. (a) 11.6% (b) M (c) m (d) (a) 13.4% (b) 1.76 M (c) 1.8 m (d) (a) 12.1 M (b) 10.1 m (c) PRACTICE COLLIATIVE PROPERTIES ANSWERS 1. (a) 30.8 torr (b) 88.6 torr (c) 13.4 torr 2. (a) torr (b) 30.2 torr 3. (a) 101.4ºC (b) 80.2ºC 4. (a) -8.96ºC (b) -1.1ºC 5. (a) 280 atm (b) 26.0 atm 6. (a) 190 g/mol (b) 60.0 g/mol (c) 2,950 g/mol