-
What is the definition of Vapor Pressure?
a measure of the collisions of the molecules with the container
-
What is saturated vapor pressure?
In a closed container, when the number of molecules entering the gas phase equals the number of molecules entering the liquid phase
-
What is volatility?
the tendency of a liquid to enter the gas/vapor phase
-
vapor pressure and temperature are ________ related
directly
As temp increases, vapor pressure increases. As temp decreases, vapor pressure decreases.
-
How does a change in atmospheric pressure affect the boiling point of a substance?
As atmospheric pressure decreases, so does it's boiling point.
-
What is boiling point?
The temperature at which vapor pressure = atmospheric pressure.
-
Why does it take longer to cook things in areas with lower atmospheric pressures?
Because the boiling point is where vapor pressure = atmospheric pressure. Since atmospheric pressure is lower, liquid boils at a lower temperature, therefore taking longer to cook things.
-
What 3 things does vaporization of an anesthetic agent depend upon?
- 1) vapor pressure of the agent
- 2) ambient temperature
- 3) amount of carrier gas flow
-
If you decrease the temperature of a liquid agent, what will happen to the rate of evaporation?
it will decrease
-
What happens to the temperature of the liquid and container as an agent evaporates?
It cools due to the loss of kinetic energy
-
What are two characteristics of a vaporizer that help prevent slowing of the evaporative rate?
- 1) high thermal conductivity (steals heat from environment)
- 2) high thermal capacity (keeps heat from environment)
-
What is the saturated vapor pressure and boiling point of halothane at STP?
-
What is the saturated vapor pressure and boiling point of Isoflurane @ STP?
-
What is the saturated vapor pressure and boiling point of sevoflurane at STP?
-
What is the saturated vapor pressure and boiling point of Desflurane at STP?
-
What 2 things does saturated vapor pressure depend upon?
- 1) agent
- 2) ambient temperature
-
If agent 1 has a saturated vapor pressure of 100 mm Hg and agent 2 has a saturated vapor pressure of 200, which agent is more volatile?
agent 2 - volatility is directly related to saturated vapor pressure
-
If agent 1 is very volatile and agent 2 is less volatile, which agent will have a higher boiling point?
agent 2 - volatility is inversely related to boiling point
-
How do you calculate the volumes percent of a vapor?
partial pressure/atmospheric pressure
-
How do you calculate the partial pressure of a gas?
multiply the percent x atmospheric pressure
-
What is the purpose of fresh gas flow through a vaporizer?
To dilute the vapors to a clinically safe and useful level
-
What are the 2 categories of vaporizers?
- 1) variable by-pass
- 2) dual-circuit
-
What type of vaporizer does desflurane use?
dual-circuit Tec 6, the carrier gas is not split. Fresh gas flow does not come into direct contact with vapors until the outlet.
-
What is the difference in heating between the Tec 6 and the Tec 4/5?
Tec 6 is electronically heated, Tec 4/5 use automatic temp compensation from the material of the vaporizer/ambient temp
-
How does a variable bypass vaporizer control the amount of anesthetic the patient receives?
the % dial increases or decreases resistance to flow which proportionally increases or decreases the amount of fresh gas flow comes into contact with the vapor
-
What is latent heat of vaporization?
the amount of heat required to convert 1 ml of liquid into a vapor
-
What is the latent heat of vaporization of desflurane?
39 C
-
How many cc's of gas to ml of liquid agent for Isoflurane?
206
-
How many cc's gas to ml of liquid agent for halothane?
240
|
|
