L13 - Gas law, partial pressures

Question 1

What is the effect of increasing gas temperature and keeping pressure constant?

Answer 1

-Volume expansion
-V is directly proportional to temperature only at CONSTANT PRESSURE.
- as temperature increases, the gas moelcules move faster and spread out, causing the gas volume to increase.

Question 2

What is the effect of 👆 sing gas volume and keeping temp. constant?

Answer 2

-Pressure 👇ses
-P is directly proportional to 1/V at constant temperature.
-If volume increases, the pressure 👇ses bc gas molecules have more space to move and collide less frequently with container walls.

Question 3

Define Partial pressure

Answer 3

The pressure exerted by a gas, whether alone or in a mixture and depends upon number of gas molecules is found in the given volume and temperature.

Question 4

Calculate partial pressure

Answer 4

partial pressure = fractional concentration of gas x total pressure of gas

Question 5

Functions of the upper airway

Answer 5

-filtering - nasal hair filters ducts.
-warming - prevent cold air reaching alveoli.
- humidifying - 👆sing water vapour>wet air>wet lungs = gases diffuse better through wet surfaces.

Question 6

Why do we do 21% x (101-6)kPa when calculating total p.p of O2 in the room?

Answer 6

-water pressure in lungs is 6kPa.
-available pressure for O2 and other gases is reduced, PH2O displaces gas molecules equally so must be subtracted to calculate dry gas pressure.
-This is important because it changes how much oxygen is available for diffusion into the blood.

Question 7

Explain BTPS conditions and ATPS conditions in Boyle-Charles formula.

Answer 7

In the lungs, gases are at Body Temperature, body Pressure and fully Saturated with water vapour at that temperature(BTPS conditions)

Volumes collected are usually at Ambient Temperature, ambient Pressure and Saturated with water vapour at that temperature (ATPS conditions).

Ambient - something that exists in the immediate environment like temperature of the surrounding air.