Acids Bases And pH Flashcards
What is arrhenius’ model of acids and bases
Acids release H+
Alkalis release OH-
When aqueous
What is bronstead lowrys model of acids and bases
Acid is a proton donor
Bases are proton acceptor
What is a conjugate acid base pair
Two species that can be interconverted by the transfer of a proton
What does mono di and tri basic mean
Mono =1 di=2 tri=3
Number of hydrogens able to be replaced during neutralisation
How do you construct an ionic equation
Spilt aqueous compounds into ions
Remove spectator ions (ones that don’t change state)
Why was the pH scale made?
To make the change in [H+] more easy to visualise
How does the hydrogen ion concentration change with 1 2 and 3 increase in pH
X10
X100
X1000
How is pH of a strong acid calculated?
Since [Ha] =[H+] (completely dissociates)
Then use conc of acid to calculate pH
Define a strong acid
Completely dissociates when aqueous
Define weak acid
Partially dissociates when aqueous
What is Ka
Equilibrium constant for the dissociation of a weak acid
What affects Ka
Temp
Compare the position of equilibrium of weak acids with large and small Ka’s
Larger Ka= pe to right
How can Ka be used to compare the strength of weak acids
Calculate pKa
What assumptions are used when calculating the Ka of a weak acid
The acid dissociates to produce equal quantities of products
Weak acid only partially dissociates so H+ produced is negligible
All H+ comes from the dissociation of the acid
