AP Chem ch 6

def pressure

measure of force exerted per unit area ( as gas molecules strike surface around them)

the lower amount of particles the lower the — and —

force and pressure

the number of gas particles with an increasing altitude —-

decreases due to lower atmospheric pressure

1mmHg = ? torr

1

1 atm + ? mmHg

760

1 atm = ? Pa

101,325

1 atm = ? Hg

29.92

manometer

instrument used to determine gas sample

pressure of gas sample relative to atomspheric pressure

if pressure of a sample in a manometer is higher than atmospheric pressure than mercury level is on the — side

left side higher than the right

4 basic properties

pressure volume temp and amount of gas (mol)

Boyles law concept

volume inversely proportional to pressure

in boyles law as pressure decreases —

volume increases

boyles law equation

P₁V₁ = P₂V₂

Charles law concept

volume directly related to temp

for temperature always convert to

Kelvin

in charles law if temp increases —

volume increases

in boyles law when the volume decreases, the same number of gas particles are in the volume causing —

more collisions aka higher pressure

in chalres law if the temp of particles increase —

particles move faster meaning more collisions

charles law equation

V₁ / T₁ = V₂ / T₂

Avogadro’s law concept

volume directly related to amount of mols

Avogadro’s law equation

V₁ / n₁ = V₂ / n₂

in Avogadro’s law if volume increases the —

amount of mol increases

ideal gas law concept

combines all 3 gas laws to one

ideal gas law

Pv=nRT

molar volume

volume occupided by 1 mol of substance

STP

22.4 L/ 1 mol

denisty of a gas equation

d = PM/ RT M = molar mass

denisty of a gas is —— portional to its molar mass

directly

to find for molar mass of a gas

use Pv=nRt to solve for mol and put mass given in problem/ mol found

partial pressure

pressure exerted by individual component of a gas mixture

total pressure

sum of all partial pressures

Pa = X_aP_total

equation of finding either partial pressure, total pressure or mole fraction

X_{a (mol fraction)}

mol of substance/ total mol

if given mass of A and want pressure

convert to mol of B and plug in value in Pv=nRT

kinetic molecular theory of gas

• gas consists of small particles that move randomly with high velocity

• attractive forces between particles of gas are very small

• volume occupied by gas particles practically nothing compared to volume gas occupies

• gas particles are in constant motion, moving in fast straight paths

• average kinetic energy of gas particles = Kelvin temp

if temp increases then there is — motion

faster (bc motion nof particles due to thermal temp)

elastic collision

exchange of energy but no loss of energy

inelastic collision

energy dissipates and comes together

lighter atoms (lower molar mass) move at a — velocity than ones heavier than them

faster

when comparing temp and pressure use — equation

P/T = P/T

units of density

g/L

finding pressure over water

• start with finding partial pressure by subtracting total pressure from pressure of H2O

• convert mmHg to atm

• use this value to plug into Pv=nRT and find mol of your value

• (if ask for g) convert mol to gram

when does gas preform non ideally

low temp, high pressure, high intermolecular forces and big molecular size