QUESTION
NEED HELP ASAP. ONLY ANSWER IF YOU ARE SURE.
1a. You are asked to prepare a buffer solution with a total volume of 250mL. You have available to you 3.0M trifluoroacetic acid (MW: 114.02 g/mol, d = 1.49 g/mL) and sodium trifluoroacetate (MW: 136.01 g/mol). The final concentration for the acid in your buffer should be 0.4M and the final concentration for the base in your buffer solution should be 0.4M. Note: if the concentration of a component is not given, you can assume that it is a solid.
How much base do you need (in g)? Record your answer with 2 digits after the decimal point.
1b. Consider the table below. Which acid and conjugate base pair would be suitable to use for the preparation of a buffer solution with a pH of 7.07?
Acid |
Ka |
Conjugate Base Salt |
|
A |
Oxalic acid |
5.4 x 10-2 |
Sodium hydrogen oxalate |
B |
Hydrofluoric acid |
3.5 x 10-4 |
Sodium Fluoride |
C |
Carbonic acid |
4.3 x 10-7 |
Sodium bicarbonate |
D |
Boric acid |
7.3 x 10-10 |
Sodium Dihydrogen Borate |
E |
Disodium hydrogen phosphate |
2.2 x 10-13 |
Trisodium phosphate |