Chapter 19: Equilibrium Flashcards
Explain what a homogenous equilibrium is.
Where all the reactants and products have the same state.
What must you remember when calculating the Kc from a HETEROgenous equilibrium?
To only include the species that are (aq) or (g) and ignore all solids and liquids.
When are the volumes of different gases contain the same number of moles of gas molecules?
When under the same conditions of temperature and pressure.
What is MOLE FRACTION ad what do the sum of all mole fractions in a gas mixture equal to?
mole fraction = number of moles of A/ total number of moles in a gas mixture
equal to 1
What is the equation for partial pressure?
mole fraction of A x total pressure
What is the sequence of calculations you should do when working out Kp?
initial moles, moles made/used, mole fraction, pp,
What is partial pressure proportional to when calculating the equilibrium constant?
Concentration
What are the suitable units used for pp when calculating Kp?
kPa, atm, Pa
What should you never do when writing out the Kp worded equation?
do NOT use sqaure brackets! (this is only for concentrations) use rounded brackets instead
What is Kc/Kp affected by?
ONLY temperature
What happens when the forward reaction is exothermic and temperature is increased?
- Kc value decreases
- decreases the equilibrium yield of products
- shifting position of equilibrium to the left
What happens when the forward reaction is endothermic and the temperature is increased?
- Kc value increases
- increases the equilibrium yield of products
- shifts position of equilibrium to the right
Why does the equilibrium position shift when the Kc value is changed due to temperature?
Because the [products]/[reactants] ratio is higher/lower than the new Kc value and so it must either increase reactant conc and decrease product conc / decrease reactat conc and increase product conc for it to equal Kc.
What happens when the concentration is increased?
Kc value does not change but since the [product]/[reactant] ratio is different the equilibrium positions shifts to make alterations for the two to equal again.
What happens when the pressure is increased?
Kp value does not change but new pp ratio does not equal the Kp value and must make alterations do go back
