1)what is the final pH of CHECOOH 0.18M ,CHECOONa 0.08M, HNO3 0.08M and NaOH 0.08M ? Ka=1.8^10(-5)
2)what fraction of free edta is in the form )y^4-) at ph=10?
The HNO3 and NaOH exactly neutralize each other to produce H2O. The remainder can be calcualted by the Henderson-Hasselbalch equation
pH = pKa + log (base)/(acid)
base is CH3COONa
acid is CH3COOH
pKa is 4.74
To find the final pH in the first question, we need to consider the dissociation of acetic acid (CH3COOH) and sodium acetate (CH3COONa). Let's break it down step by step:
Step 1: Write down the dissociation reaction of acetic acid:
CH3COOH ⇌ CH3COO- + H+
Step 2: Write down the dissociation reaction of sodium acetate:
CH3COONa ⇌ CH3COO- + Na+
Step 3: Identify the spectator ions (ions that do not participate in the reaction):
In this case, Na+ and NO3- are spectator ions.
Step 4: Construct the net ionic equation:
H+ + CH3COO- ⇌ CH3COOH
Step 5: Calculate the initial concentration of CH3COOH:
Given that [CH3COOH] = 0.18 M
Step 6: Calculate the initial concentration of CH3COO-:
Given that [CH3COONa] = 0.08 M, and since CH3COONa dissociates into CH3COO- and Na+, the initial concentration of CH3COO- is also 0.08 M.
Step 7: Calculate the concentration of H+ at equilibrium:
Since CH3COOH is a weak acid, we can use the equilibrium equation and the acid dissociation constant (Ka = 1.8 x 10^-5) to find the concentration of H+ at equilibrium. The equation is given by: Ka = [CH3COO-][H+]/[CH3COOH]
Step 8: Use the Henderson-Hasselbalch equation to find the pH:
The Henderson-Hasselbalch equation is given by: pH = pKa + log([A-]/[HA]), where pKa is the negative logarithm of the acid dissociation constant Ka. In this case, [A-] is the concentration of CH3COO- and [HA] is the concentration of CH3COOH.
For the second question, to find the fraction of free EDTA in the form (Y^4-), we need to consider the equilibrium reactions involving EDTA and its various forms.
Unfortunately, you have not provided the specific equilibrium reactions involving EDTA at pH 10. Therefore, I cannot proceed with the calculation without additional information.