Topic 11 - Equilibrium II Flashcards
State Avogadro’s Law
Equal volumes of different gases contain the same number of particles under the same conditions of temperature and pressure
What is the only condition that will change the value of Kc or Kp?
Temperature
Why is Avogadro’s Law useful ?
It helps us convert a question stating gas volumes -> a statement about reacting moles -> a chemical equation
Total pressure = …
sum of partial pressures
State Dalton’s Law of partial pressures
The partial pressure, p, of any gas in a mixture of gases is the pressure that the gas would exert if it alone occupied the same volume at the same temperature
What is the equation for the partial pressure of a gas?
partial pressure, p, of a gas = molar fraction x total pressure
What is a molar fraction?
Moles of X (g)/ total number of moles of X (g) + Y (g)
What is the molar volume?
Under standard conditions, 298K + 100 kPa, one mole of any gas occupies 24dm^3
What is the equation for the volume of a gas?
volume = molar volume x moles (of gas)
What is the only phase that is included in the Kp expression of a reaction?
gas
What do you not use in the Kp expression that you do use in the Kc expression?
[] square brackets - as this indicates concentrations
Write a Kp expression for the reversible reaction with the general equation:
aA + bB <=> cC + dD (all in gaseous state)
Kp = pC(g)^c x pD(g)^d / pA(g)^a x pB(g)^b
where all partial pressures are AT EQUILIBRIUM
What is the letter that indicates partial pressure?
slanted p
What are the units of partial pressure?
atm
How do you find the units of Kp?
Use indices laws with atm as the unit for partial pressure
NB: Kp can have no units as atm’s can cancel out
