Pretty sure it's the Precambrian.
We are given
0.2 M HCHO2 which is formic acid, a weak acid
and
0.15 M NaCHO2 which is a salt which can be formed by reacting HCHO2 and NaOH
The mixture of the two results to a basic buffer solution
To get the pH of a base buffer, we use the formula
pH = 14 - pOH = 14 - (pKa - log [salt]/[base])
We need the pKa of HCO2
From, literature, pKa = 1.77 x 10^-4
Substituting into the equation
pH = 14 - (1.77 x 10^-4 - log 0.15/0.2)
pH = 13.87
So, the pH of the buffer solution is 13.87
A pH of greater than 7 indicates that the solution is basic and a pH close to 14 indicates high alkalinity. This is due to the buffering effect of the salt on the base.
Answer:
S = 1.1 × 10⁻⁹ M
Explanation:
NaCl is a strong electrolyte that dissociates according to the following expression.
NaCl(aq) → Na⁺(aq) + Cl⁻(aq)
Given the concentration of NaCl is 0.15 M, the concentration of Cl⁻ will be 0.15 M.
We can find the molar solubility (S) of AgCl using an ICE chart.
AgCl(s) ⇄ Ag⁺(aq) + Cl⁻(aq)
I 0 0.15
C +S +S
E S 0.15+S
The solubility product (Ksp) is:
Ksp = 1.6 × 10⁻¹⁰ = [Ag⁺].[Cl⁻] = S (0.15 + S)
If we solve the quadratic equation, the positive result is S = 1.1 × 10⁻⁹ M
