Equilibria

Acids are proton [blank_start]donors[blank_end]

Acids are [blank_start]electron pair[blank_end] acceptors

[blank_start]Strong[blank_end] acids completely dissociate

Weak acids [blank_start]partially[blank_end] dissociate to set up an equilibrium

More H+ ions mean a stronger acid because there are [blank_start]more protons to donate[blank_end]

Weaker acids dissociate less so equilibrium moves to the [blank_start]left[blank_end]

Strong bases completely dissociate into [blank_start]ions[blank_end] in an [blank_start]aqueous[blank_end] solution

[blank_start]Weak[blank_end] bases partially react to give ions. An equilibrium is set up when they dissolve in [blank_start]water[blank_end].

Buffer solutions are solutions which resist changes in [blank_start]pH[blank_end] when small quantities of [blank_start]acid[blank_end] or [blank_start]alkali[blank_end] are added.

The are two types of buffer solution, [blank_start]alkaline[blank_end] and [blank_start]acidic[blank_end].

Buffer solutions must be made of [blank_start]weak[blank_end] acids and bases so that an [blank_start]equilibrium[blank_end] is present. This allows ions to be removed and produced. Strong acids can't be used as they fully dissociate so [blank_start]H+[blank_end] can't be removed.

Buffer solutions are found in the [blank_start]stomach[blank_end] and the blood.

Calculate the pH of 0.1M of HCl

The dissociation constant for a weak acid is given the symbol ...

Weaker acids dissociate less to give [blank_start]fewer[blank_end] ions so [blank_start]Ka[blank_end] is smaller but pKa is larger.

An acid with more [blank_start]Cl[blank_end] is a stronger acid because the anion is more stable due to electron [blank_start]withdrawing[blank_end] effect.

What is the symbol for the equilibrium constant?

Calculate the pH of 0.001M NaOH...

Kw varies with temperature

Find the H+ conc in 0.01moldm-3 solution of NaOH...

Many indicators are [blank_start]weak[blank_end] acids as they [blank_start]partially dissociate[blank_end] in solution. The removal of the [blank_start]H+[blank_end] ion causes a colour change.

Indicate on the image at what point in the titration a suitable indicator would change colour: For boxes you believe to be incorrect insert - x In the box you believe to be correct write - indicator

What is involved in the titration of these curves?

The 3 steps in calculating the pH of a buffer solution are as follows: 1- convert Ka to [blank_start]pKa[blank_end] using [blank_start]-log[blank_end] 2-place values into equation pH=pKa+ log [[blank_start]base[blank_end]] / [[blank_start]acid[blank_end]] 3- calculate the pH

At what point during an acid base titration does a concentrated acid = concentrated conjugate base

[blank_start]Le Chateliers[blank_end] principle may be used to predict whether or not an indicator will change colour.

pH + [blank_start]pOH[blank_end] = 14

Calculate the pH if H+ is 3x10 to the power of -4

Calculate the H+ present in a solution of pH 12.7