Answer:
1. pH = 1.23.
2. 
Explanation:
Hello!
1. In this case, for the ionization of H2C2O4, we can write:

It means, that if it is forming a buffer solution with its conjugate base in the form of KHC2O4, we can compute the pH based on the Henderson-Hasselbach equation:
![pH=pKa+log(\frac{[base]}{[acid]} )](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D%20%29)
Whereas the pKa is:

The concentration of the base is 0.347 M and the concentration of the acid is 0.347 M as well, as seen on the statement; thus, the pH is:

2. Now, since the addition of KOH directly consumes 0.070 moles of acid, we can compute the remaining moles as follows:

It means that the acid remains in excess yet more base is yielded due to the effect of the OH ions provided by the KOH; therefore, the undergone chemical reaction is:

Which is also shown in net ionic notation.
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Answer:
The concentration of H⁺ in a 2.5 M HCl solution is 2.5 M
Explanation:
As HCl is a strong acid and hence a strong electrolyte, it will dissociate as
HCl ⟶ H⁺ + Cl⁻
So, The concentration of H⁺ will be 2.5 M (same as HCl)
Thus, The concentration of H⁺ in a 2.5 M HCl solution is 2.5 M
<u>-TheUnknownScientist</u><u> 72</u>
Answer:
151.4863 years
Explanation:
Half life, t1/2 = 100 years
Initial concentration,[A]o = 100%
Final concentration, [A] = 35% (after 65% have been decayed)
Time = ?
Half life for a first Order reaction is given as;
t1/2 = ln (2) / k
k = ln(2) / 100
k = 0.00693y-1
The integral rate law for first order reactions is given as;
ln[A] = ln[A]o − kt
kt = ln[A]o - ln[A]
t = ( ln[A]o - ln[A]) / k
t = [ln(100) - ln(35)] /0.00693
t = 1.0498 / 0.00693
t = 151.4863 years
The concentration of diluted solution is 0.756M.
From the question given above, the following data were obtained:
Volume of stock solution (V1) = 18.9 mL
Molarity of stock solution (M1) = 10 M
Volume of diluted solution (V2) = 250 mL
Molarity of diluted solution (M2) =?
We can obtain the molarity of the diluted solution by using the dilution formula as shown follow:
M1V1 = M2V2
10 × 18.9 = M2 ×250
189 = M2 × 250
Divide both side by 100
M2 = 189 / 250
M2 = 0.756 M
Therefore, the molarity of the diluted solution is 0.756 M.
Thus the concluded that concentration of the dilute acid is 0.756 M.
Learn more about concentration of diluted solution: brainly.com/question/10725862
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