NOTES (kap. 1,3,1)

Question 1

what is the ideal gas equation used to describe

Answer 1

Is used to describe the behavior of gasses at low pressures, and is based on below assumptions:

• gas particles have negligible volume
• intermolecular forces between gas particles do not occur
• collision between gas particles are perfectly elastic (no loss of kinetic energy during collision)
• gas particles are in constant, random motion and no time spent in collision.

Foroven er en beskrivelse af en ideel gas/perfect gas, og kan beskrives ved brug af ovenstående formel. For de fleste tilfælde (i opgaver og LAB) er det acceptabelt at antage at det er en ideal gas man har med at gøre.

Question 2

Hvad er forskellen på en ideel gas og en ideel opløsning?

Answer 2

I en ideel gas → Molekyler har ingen interaktioner overhovedet.

I en ideel opløsning → Molekyler har interaktioner, men de er lige stærke mellem alle typer molekyler.

Question 3

How do you calculate the pressure applied to a gas that is a part of a mixture of gases?

Answer 3

Daltons law of partial pressures (The total pressure exerted by the mixture of gases is
equal to the sum of the partial pressures of the individual gases.)

The criteria met is that the gases are non
reactive and exhibit ideal behavior.

Question 4

Often we may be more interested in the pressure of a single gas in a mixture than in the total pressure.

Answer 4

For instance in PO2 and PCO2 when handling living tissue or organisms.