Solutions Review

Solutions Review

Solutions Review

  1. List three ways to determine which part is the solute and which part is the solvent in a solution.
  • Solute is the substance being dissolved and the solvent is the substance doing the dissolving (used with solid-liquid and gas-liquid solutions)
  • Solute occurs in a smaller amount than the solute (used when both are in same phase)
  • Solute is the substance that is in a different phase than the resulting solution
  1. When water occurs in a solution, it is almost always the __solvent____ of the solution.
  1. What are the differences between a true solution, a colloid, and a suspension?

True solution has very small particle sizes for the solute. The particles will not settle out of the solution, and the solution will have the same appearance throughout. Colloids have medium particle sizes. The particles will not settle out of the solution either, and it will also have the same appearance throughout. Colloid particle will disperse light whereas true solution particles will not. Suspensions have the largest particle sizes. The particles will settle out of the mixture, and they have a heterogeneous appearance throughout.

  1. What does “like dissolves like” mean?

Polar tends to dissolve polar, and nonpolar tends to dissolve nonpolar

  1. Which solute would dissolve in gasoline?
  2. CaCO3
  3. CH4
  4. KI
  1. What is the difference between an electrolyte and a nonelectrolyte? What are their corresponding i values?

Electrolyte break apart into ions during salvation which means their solutions will carry electrical current. Their i value will be equal to however many pieces they break into. Nonelectrolytes will not break into ions during salvation. The solutions will not carry a current. Their i value will be 1.

  1. What is the molarity of a solution that is made with 0.25 moles of LiF to make 1.50 L of solution?

x = 0.25 mol LiF / 1.50 Lx = 0.167 M LiF

  1. What is the molarity of a solution that is made with 135 g of Mg3N2 dissolved to make 800 ml of solution?

800 mL x 1 L = 0.800 L

1 1000 mL

135 g Mg3N2 x 1 mol Mg3N2 = 1.337693222 mol Mg3N2

1 100.92 g Mg3N2

x = 1.337693222 mol Mg3N2/ 0.800 Lx = 1.67 M Mg3N2

  1. How many grams of KI must be dissolved in 500 g of water to make a 0.0600 m KI solution?

500 g x 1 kg = 0.500 kg

1 1000 g

0.0600 m = x/ 0.500 kgx = 0.03 mol KI

0.03 mol KI x 166.01 g KI = 4.98 g KI

1 1 mol KI

  1. Calculate the molality of a solution containing 16.3 grams of a molecular compound of Urea (CH4N2O), in 600 mL of water.

600 g x 1 kg = 0.600 kg

1 1000 g

16.3 g CH4N2O x 1 mol CH4N2O = 0.271395271 mol CH4N2O

1 60.06 g CH4N2O

x = 0.271395271 mol CH4N2O / 0.600 kgx = 0.452 m CH4N2O

  1. Calculate the boiling point for a solution containing 1250 grams of glucose (C6H12O6), in 3256 mL of water.

3256 g x 1 kg = 3.256 kg

1 1000 g

1250 g C6H12O6 x 1 mol C6H12O6 = 6.938277087 mol C6H12O6

1 180.16 g C6H12O6

x = 6.938277087 mol C6H12O6/ 3.256 kgx = 2.130920481 m C6H12O6

Tb = (1)(0.512 °C kg/mol)( 2.130920481 m) = 1.091031286 °C

Tbsolution = 100 °C + 1.091031286 °C = 101 °C

  1. What is the freezing point for a solution containing 357 grams of a molecular compound ethanol (CH3CH2OH), dissolved in 300 grams of water.

300 g x 1 kg = 0.300 kg

1 1000 g

357 g CH3CH2OH x 1 mol CH3CH2OH = 7.749077491mol CH3CH2OH

1 46.07 g CH3CH2OH

x = 7.749077491mol CH3CH2OH / 0.300 kgx = 25.8302583 m CH3CH2OH

Tf = (1)(1.86 °C kg/mol)( 25.8302583 m) = 48.04428044 °C

Tfsolution = 0 °C - 48.04428044 °C = -48.0 °C

  1. Circle the solution in the pair below that would have the highest boiling point.
  2. 0.25 m saltwater
  3. 0.40 m saltwater
  1. Circle the solution in the pair below that would have the highest boiling point.
  2. 0.5 m C2H5OH
  3. 0.5 m Ca3(PO4)2
Top View