Henry’s law states
that at a given temperature the amount of gas dissolved in a liquid is directly proportional to the partial pressure of gas in equilibrium with the liquid. Increasing the temperature will decrease solubility of gas dissolved in the fluid causing bubbles to form.
- Henry’s Law (Gas solubility ∝ Pressure)
“Henry drinks soda.”
More pressure → more gas dissolves in liquid.
When you open a soda can, pressure drops → bubbles escape.
Gay-Lussac’s law
states for an ideal gas pressure of a given mass of gas varies directly with the absolute temperature of gas when volume is kept constant.
- Gay-Lussac’s Law (P ∝ T at constant V)
“Gay-Lussac’s tires explode.”
At constant volume, if Temperature ↑ then Pressure ↑.
Think: car tires bursting on a hot day.
Graham’s law
states the rate of diffusion of a gas varies inversely with the square root of its molecular weight.
Dalton’s law
.
relates to total pressure of a mixture of gases.
- Dalton’s Law of Partial Pressures (Total P = sum of individual gases’ pressures)
“Dalton adds pressures.”
The total pressure of a mixture = the sum of the parts.
Like roommates each adding money into the rent jar → total = everyone’s contribution.
Charles’s law
states that for an ideal gas volume of a given mass of gas varies directly with the absolute temperature of gas when the pressure is kept constant (expands when heated)
- Charles’s Law (V ∝ T at constant P)
“Charles likes to party with hot air balloons.”
Charles’s Law says Volume ↑ as Temperature ↑.
Think: heat a balloon → it expands.
While turbulent flow is by its very nature unpredictable, it is thought to have the following characteristics:
Flow is proportional to the radius squared
Flow is proportional to the square root of the pressure gradient
Flow is inversely proportional to the length and density of the fluid
COSSH specifies that for people exposed to anaesthetic agents the maximum occupational exposure over an 8 hour period is 100 ppm for nitrous oxide, 50 ppm for enflurane, isoflurane and desflurane, 10 ppm for halothane. Whilst no recommendation is made for sevoflurane the manufacturers recommend an occupational exposure of 20 ppm.
