Lecture 7 - Solutions and Solubility - Chemistry & Physics of Anesthesia Flashcards
What is a solution?
A solution is a solute dissolved in a solvent
what is a suspension?
A suspension is when the solute DOES NOT dissolve in the solvent.
What is a colloidal solution?
A colloidal solution is when particles exist in solution somewhere between a true solution and a true suspension.
What is a solution?
A solution is when a solute completely dissolves in a solvent.
What is a suspension?
A suspension is when the solute does not dissolve in the solvent.
What is a colloidal solution?
A colloidal solution is when the particles exist somewhere between the solution and suspension state.
What is the definition of a solution?
A solution is a homogeneous mixture of two or more components.
What is the dissolving agent in a solution?
The solvent is the dissolving agent in a solution.
What is the substance that is dissolved in a solution?
The solute is the substance that is dissolved in a solution.
What are the types of particles in the solution?
Atoms, ions, molecules (sugar and water)
Are the particles in suspension larger or smaller than those in solution or colloidal solutions?
The particles in suspension are larger than those in solution or colloidal solution.
What is the dispersement of the particles in a suspension?
The particles in a suspension can be evenly distributed by mechanical means (i.e. shaking the contents), but eventually the particles will settle out (i.e. oil and water)
Will particles settle out in a colloidal solution?
No! The size of particles in between those found in solutions and suspensions and can be mixed in such a way that they remain evenly distributed without settling out.
What is the mixture of a colloidal solution called?
The mixture the particles form in a colloidal solution is called a colloidal dispersion. A colloidal dispersion consists of colloids in a dispersing medium (i.e. milk)
What is a solvent?
A solvent is a substance in which a solute is dissolved.
- usually a liquid
- a solvent is the dissolving medium of the solute
How does a solvent work to dissolve a solute?
The solvent particles surround the solute particles. The forming of a solution is physical process not a chemical one.
Is forming a solution a physical or chemical process?
Forming a solution is a physical process, NOT a chemical one. The solvent particles are simply surrounding the solute particles.
What is the universal solvent?
water is the universal solvent.
What is the solvent in body fluids?
Water is the solvent in body fluids.
What is a true solution?
A true solution is when the solute is completely dissolved in the solvent.
- this is a physical change
- solute can be a solid, liquid, or a gas
What dictates the amount of solute dissolved in solvent?
Temperature dictates the amount of solute dissolved in a solvent.
Will the solubility of a solid increase or decrease with increasing temp?
The solubility of a solid will increase with increasing temp
Will the solubility of a gas increase or decrease with increasing temperature?
The solubility of a gas will decrease with increasing temperature.
As the temperature increases will the solid become more or less soluble?
As the temperature increases, a solid becomes more soluble.
As the temperature increases will the gas become more or less soluble?
As the temperature increases, the gas becomes less soluble.
What determines how much solid solute is dissolved in a solvent?
Temperature, the amount of solid that dissolves in a solvent is usually directly proportional to the temperature.
- as the temperature increases, the solubility of the solid increases.
- as the temperature decreases, the solubility of the solid decreases.
What affects the solvents ability to dissolve solute?
The nature of the solvent affects the amount of solid that dissolves in the solvent.
What is a better solvent: water or ethanol?
Water is a better solvent than ethanol.
- water is more polar than ethanol
- water dissolves polar substances better than ethanol
As you increase the temperature, what happens to the solubility of glucose (solid)?
As you increase the temperature, the solubility of glucose increases because glucose is a solid.
What determines the solubility of a gas in a solvent?
The solubility of a gas in a solvent depends on the nature and the temperature of the solvent.
What is the relationship between increasing temperature and gas solubility?
As the temperature increases, the less gas that will dissolve in solution.
-the greater the temperature of the solvent (liquid), the less gas that will be dissolved in the solvent
What are the anesthesia implications of the relationship between temperature and gas solubility with increased temperature of solvent?
As the patients temperature increases, the gas solubility decreases. Therefore, as patient temperature increases the less anesthetic is dissolved and it is more difficult to anesthetize the patient.
(think: increased temperature = increased MAC requirement)
- as you increase the temp you decrease the partial pressure of the gas.
What are the anesthesia implications of the relationship between temperature and gas solubility with decreased temperature of solvent?
A the patients temperature drops, the more anesthetic is dissolved easier, the easier to anesthetize.
(think: decrease temperature = decreased MAC requirement)
- as you decrease the temp, you increase the partial pressure of the gas.
What is the relationship between gas solubility and temperature?
THE GREATER THE TEMPERATURE, THE LESS SOLUBLE THE GAS. THE GREATER THE TEMPERATURE OF THE SOLVENT, THE LESS GAS WILL BE DISSOLVED IN THE SOLVENT
Why is it that the increased temperature, causes a decrease in the amount of gas dissolved in the solvent?
The increased temperature, increases the KE of the gas molecules and breaks the IMF between the gas and solvent. Therefore, gas escapes from the solution.
-the increased KE with increased temp is the same reason for the increase in vapor pressure with increased temperature.
Bottomline: the greater the temperature, the less gas dissolved in the solute.
What is Henry’s law?
The amount of gas dissolved in a liquid is directly proportional to the pressure applied to the gas as it overlies the liquid.
(think: of a hen sitting on eggs, giving the eggs pressure)
- the increase in pressure, the more gas dissolved in the liquid
- a decrease in pressure, the less gas dissolved in the liquid
According to Henry’s Law, as the pressure applied to the gas layer increases, what happens to the solubility of the gas in the liquid?
As the pressure applied to the gas layer above the liquid increases, the solubility of the gas in the liquid increases.
According to Henry’s Law, as the pressure applied to the gas layer above the liquid decreases, what happens to the solubility of the gas in the liquid?
As the pressure applied to the gas layer above the liquid decreases, the solubility of the gas in the liquid decreases.
What does Henry’s Law state?
The amount of gas dissolved in a liquid is directly proportional to the pressure applied to the gas as it overlies the liquid.
(think: a hen sitting on eggs exerting a pressure on the eggs)
Is pressure applied to a gas directly or inversely proportional to gas solubility?
The pressure applied to a gas is directly proportional to gas solubility
- as the pressure applied increases, the gas solubility increases
- as the pressure applied to the gas decreases, the gas solubility decreases
Is temperature of the solvent directly or inversely proportional to gas solubility?
Temperature is inversely proportional to gas solubility.
- As the temperature of a solvent increases, the gas solubility decreases.
- As the temperature of a solvent decreases, the gas solubility increases.
What is a saturated solution?
The state of solution in which more solute cannot be added without some of the solute precipitating out of the solution (or vaporizing out of solution)
aka a saturated solution is one what the maximum amount of solute has been dissolved in the solvent and adding anymore solute to the solvent will just result in undissolved solute
What point is incorporated in a saturated solution?
the precipitation point is included in a saturated solution?
What is the saturated solution in terms of gases and liquids mixing?
The saturated solution is the point of equilibrium between the gas and liquid phase.
- the partial pressure of the gas = the partial pressure of the liquid
What is a super-saturated solution?
A super-saturated solution is one that holds more than it can hold.
What forms when you add more solute to a saturated solution?
a precipitate forms when you add more solute to a saturated solution.
For gases and liquids, what are the partial pressures of a saturated solution?
gas partial pressure = the liquid partial pressure.
The point of equilibrium between the gas and liquid phases
What is solution strength?
Solution strength is the grams of solute/100 mL of solvent
What does % solution include?
grams of solute/100 mL of solution
What is the % solution of 0.9% NaCl?
0.9 grams NaCl/100 mL of solution
What is the % solution of D5W?
5 g dextrose/ 100 mL solution
What is molar solution?
Molar solution is moles of solute/1 liter of solvent