Answer:
6.68 X 10^-11
Explanation:
From the second Ka, you can calculate pKa = -log (Ka2) = 6.187
The pH at the second equivalence point (8.181) will be the average of pKa2 and pKa3. So,
8.181 = (6.187 + pKa3) / 2
Solving gives pKa3 = 10.175, and Ka3 = 10^-pKa3 = 6.68 X 10^-11
OK, so to answer this question, you will simply use the molality equation which is as follows:
<span>M1V1 = M2V2
In the givens you have:
M1 = 2M
V1 is the unknown
M2 = 0.4M
V2 = 100 ml
</span>plug in the givens in the above equation:
<span>2 x V1 = 0.4 x 100
</span>therefore:
V1 = 20 ml
Based on this: you should take 20 ml of the 2 M solution and make volume exactly 100 ml in a volumetric flask by diluting in water.
Answer:
1. Equivalence point
2. Direct titration
3. Primary standard
4. Titrand
5. Back titration
6. Standard solution
7. Titrant
8. Indirect titration
9. End point
10. Indicator
Explanation:
1. The equivalence point is the tiration point at which the quantity or moles of the added titrant is sufficient or equal to the quantity or moles of the analyte for the neutralization of the solution of the analyte.
2. Direct titration is a method of quantitatively determining the contents of a substance
3. A primary standard is an easily weigh-able representative of the mount of moles contained in a substance
4. A titrand is the substance of unknown concentration which is to be determined
5. The titration method that uses a given amount of an excess reagent to determine the concentration of an analyte is known as back titration
6. A standard solution is a solution of accurately known concentration
7. A titrant is a solution that has a known concentration and which is titrated unto another solution to determine the concentration of the second solution
8. Indirect titration is the process of performing a titration in athe reverse order
9. The end point is the point at which the indicator indicates that the equivalent quantities of the reagents required for a complete reaction has been added
10 An indicator is a compound used to visually determine the pH of a solution.
