Tutorial 11

Question 1

True or False
Properties of solutions are different from that of pure solvent.

Answer 1

True

Question 2

colligative properties

Answer 2

Properties that depend on the number of solute particles in solution (ions or molecules, large or small)

Question 3

True or False
The effect of a solute particle of one species is considered unequal to an entirely different kind of particle.

Answer 3

False
The effect of a solute particle of one species is considered equal to an entirely different kind of particle.

Question 4

Boiling point elevation

Answer 4

Increase in the boiling point when a solute is added

Question 5

True or False
Solution containing 34.2 g of sucrose (mol. wt. 342) in 1000 g of water has the same osmotic pressure as a solution containing 18.0 g of anhydrous dextrose, mol. wt. 180.

Answer 5

True

Question 6

Assumptions to apply CP equations:

Answer 6

• Solute is not volatile, so it does not contribute to the vapor.
• Solute does not dissolve in the solid solvent
  (solvent freezes out in the pure state rather than a solid solution containing some of the solute).

Question 7

True or False
solute affects the properties of the liquid phase alone and leaves the vapour and solid completely unaffected

Answer 7

True

Question 8

Difference between diffusion and osmosis

Answer 8

Diffusion depends on the concentration
Osmosis depends on the osmotic pressure

Question 9

Osmotic pressure

Answer 9

excess pressure that must be applied to the solution to prevent the passage of the solvent through a perfect semi-permeable membrane. The osmotic pressure is proportional to .the concentration of the solution

Question 10

Solutions that have equal osmotic pressure

Answer 10

iso-osmotic or isotonic

Question 11

Osmoles equation

Answer 11

Osmol = mol* i (number of ions)

Question 12

Which is greater the osmotic pressure of electrolytes or non electrolytes solutions?

Answer 12

The osmotic pressure of solutions of electrolytes is considerably greater than the osmotic pressure of solutions of non-electrolytes of the same molalconcentration.

Question 13

Osmotic pressure of nonelectrolytes (molarity)

Answer 13

piV = nRT

pi = osmotic pressure in atm.
V = the volume of solution in liters
n = the number of moles of solute
R = the gas constant equal to 0.082 liter atm/mole deg
T = the absolute temperature in kelvin
en/V = molar concentration of solute (ml/L)

This only applies where the solution is very dilute

Question 14

Temp in kelvin

Answer 14

°C + 273

Question 15

Osmotic pressure of nonelectrolytes (molality)

Answer 15

pi = mRT

Question 16

Osmotic pressure of electrolytes

Answer 16

piV = inRT
i = number of ions produced by the ionization of electrolyte.

Question 17

Affect of osmotic pressure on Red blood cells (erythrocytes)

Answer 17

Isotonic- no net osmotic pressure. Solutions to be injected into the blood should be isotonic with erythrocytes.

Hypotonic- solution has a lower concentration of electrolyte than in the body of cells (hemolysis)

Hypertonic- solution has a higher concentration of electrolyte than in the body of cells (shrinkage

Question 18

Physiologic osmotic pressure

Answer 18

0.28 – 0.308 osmol/L = 280 - 310 mosmol/L

0.9% NaCl = 0.308 osmol/l = 308 mosmol/L

Question 19

Oral Rehydration Solutions (ORS)

Answer 19

consists of a solution of salts and sugars
treat dehydration caused by diarrhea
lower osmolarity compared to the body (hypotonic)
decreasing the concentration of glucose and sodium chloride (NaCl).
insert a hypotonic solution to a dehydrated person so his body osmolarity is actually lower than normal, so this hypotonic solution is almost isotonic with the dehydrated body. So, by lowering the osmolarity, we are preventing the effects of hypertonicity on the net fluid absorption.

Question 20

Normal osmolarity of blood/serum

Answer 20

300-310 mOsm/L

Question 21

True or False
Hypotonic and hypertonic solutions may be infused in small volumes and into large vessels, where dilution and distribution are rapid

Answer 21

True

Question 22

Admixtures greater than 600 to 900 mOsm/L are associated with a dramatic increase in

Answer 22

phlebitis

Question 23

Hymolytic anemia

Answer 23

Very hypotonic IV solutions such as 1/4 NS cause red blood cells to swell and burst. If a sufficient number of RBC’s are so affected, the patient may develop anemia.