CI - Equilibrium constants Flashcards
What do the units of Kc depend on?
The reaction.
How do you calculate the units of Kc?
Plug all you units into your expression and cancel them out as much as possible.
What can Kc be used to work out?
Concentrations in an equilibrium mixture.
How do you work out the concentrations of components in an equilibrium mixture?
By rearranging your expression for Kc.
What sort of technique do you need to use to find the concentration of a substance in a reversible reaction at equilibrium?
A technique that won’t disturb the position of the equilibrium.
What techniques can you use to find the concentration of a substance in a reversible reaction at equilibrium?
Colorimetry or by using pH.
How can you use colorimetry to find the concentration of a substance in a reversible reaction at equilibrium?
If one of the substances in your reaction is coloured, it will absorb a particular wavelength of light. You can use colorimetry to find the absorbance of this wavelength of light at equilibrium, and use a calibration curve to calculate the concentration of the coloured ions.
How can you use pH to find the concentration of a substance in a reversible reaction at equilibrium?
If one side of your reversible reaction contains either an acid or a base, then you can use a pH probe to find the pH of the equilibrium mixture, You can then use pH calculations to find the concentration of the acid or the base at equilibrium.
If you know the initial concentrations of all your reactant, and the equilibrium concentration of one of them, you can use the reaction equation to work out what?
The concentration of all the components at equilibrium.
What can you use the concentration of all the components at equilibrium to calculate?
Kc
What helps work out equilibrium concentrations?
Initial concentrations of all reactants, equilibrium concentration of one reactant and the reaction equation.
What can you use the equilibrium concentration of a product to work out?
The equilibrium concentrations for the other products.
