Chemistry, General Chemistry II, Lab report.
Experiment 17 Hydrolysis of Salts
Experiment Hydrolysis of SaltsIn salt hydrolysis, the cations or
anions of the dissociated salt remove hydrogen ions from or donate
hydrogen ions to water (which is amphiprotic). Hydrolyzing salts
are usually derived from a strong acid and a weak base, or from a
weak acid and strong base. In hydrolysis reactions, the salt and
water react to form an acid or a base.
The anions of weak acids such as HCO3-, and cations of weak
bases, such as NH4+, do undergo hydrolysis.
The anions of strong acids (Cl-, NO3 -, etc.) and the cations of
strong bases (Na+, Ca+2, etc.) do not undergo hydrolysis.
Purpose:
To predict the pH of salt solutions
To determine the pH of salt solutions by using Indicators
solutionsMaterials needed:
Various 0.10 M salt solutions, standard sealed 8 well plate,
8-well plates, transfer pipets, buffer solutions, indicator
solutions, and a glue gun.Procedure:
1) By using the formula of the salt, predict and then record
your predicted pH in the data table.
2) Use a transfer pipet to add 2 drops of Universal indicator to
seven wells of an 8 well plate.
3) Add 5 drops of deionized water into each of the seven wells
containing the Universal Indicator.
4) In the first well, add 2 drops of the pH 3 Buffer solution.
In the second well, add 2 drops of the pH 4 Buffer solution. Repeat
until all 7 wells have 2 drops of the appropriate indicator.5) Use
the low melt glue gun to seal the open wells.
6) In another 8 well plate, add 5 drops of the appropriate salt
solution to the first well. Then add 2 drops of the Universal
Indicator solution. Match the color change to the corresponding
color in the standard sealed well plate. Note the pH of the salt
solution in the data table.
7) Continue until all the salt solutions have been
completed.
8) If time permits, choose another indicator and again construct
a sealed standard 8 well plate. Repeat the above procedure to
predict and determine the pH of the salt solutions.
9) Complete the data table.
Experiment 17 Hydrolysis of SaltsData Table:NameFormulaPredicted
pHActualpHIndicator ColorHydrolysis Reaction
