FILTRATION When the substances in a mixture have different particle sizes, they are separated by filtration. The mixture is poured through a sieve or filter. The smaller particles slip through the holes, but the larger particles do not.p
Answer:
pKa = 4.89.
Explanation:
We can solve this problem by using the <em>Henderson-Hasselbach equation</em>, which states:
pH = pKa + log ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
In this case [A⁻] is the concentration of sodium benzoate and [HA] is the concentration of benzoic acid.
We <u>input the given data</u>:
4.63 = pKa + log 
And <u>solve for pKa</u>:
pKa = 4.89
To solve this we use the equation,
M1V1 = M2V2
where M1 is the concentration
of the stock solution, V1 is the volume of the stock solution, M2 is the
concentration of the new solution and V2 is its volume.
M1V1 = M2V2
1% x V1 = 0.25% x 10 mL
V1 =2.5 mL
Therefore, you will need to have 2.5 mL of the 1% HCl solution and 7.5 mL of distilled water. In mixing the two liquids, you should remember that the order of mixing would be acid to water. So, you use a 10 mL volumetric flask . Put small amount of distilled water and add the 2.5 mL of HCl solution. Lastly, dilute with distilled water up to the 10 mL mark.