Answer:
The molar mass of the diprotic acid is 90.10 g/mol.
Explanation:
The acid is 25.0 mL of this solution required 11.1 mL of 1.00 KOH for neutralization.

To calculate the concentration of acid, we use the equation given by neutralization reaction:
( neutralization )
where,
are the n-factor, molarity and volume of diprotic acid
are the n-factor, molarity and volume of base which is KOH.
We are given:
Putting values in above equation, we get:


Molarity of acid solution = 0.222 M =0.222 mol/L
Volume of original solution = 250 mL = 0.250 L ( 1 mL = 0.001 L)
Moles of diprotic acid in 0.250 L solution :

Mass of diprotic acid = m = 5.00 g


The molar mass of the diprotic acid is 90.10 g/mol.
Answer: Concentration of NaOH calculated will be underestimated.
Explanation:
End point is an observational point , which tells us about the completion of reaction between the titrant (solution in burette) and titre(solution in conical flask) in titration experiment.
In this case , NaOH is titrant whose concentration is unknown.
, 
, 

....(1)
According to question a chemist overshoots the end point and adds to much of NaOH solution, which means increase in the value of
.
Then the value of
in equation (1), will get lowered , which means that the concentration of NaOH was lower than that of the actual value. Hence underestimated concentration of NaOH.
Answer:
15.33
Explanation:
Given parameters:
Mass of KOH = 121g
Volume of solution = 100mL = 0.1dm³
Molar mass of KOH = 56.11g/mol
Unknown:
pH of the solution = ?
Solution:
To find the pH, we must first know the concentration of the solution obtained by mixing KOH up to this volume.
This can be done by finding the molarity of the solution.
Molarity =
Number of moles of KOH =
=
= 2.16mole
Input parameters;
Molarity of solution =
= 21.6moldm⁻³
KOH → OH⁻ + K⁺
21.6 21.6 21.6
In the solution we have 21.6moldm⁻³ of OH⁻ which is need to find the pH;
pOH = -log₁₀(OH⁻)
pOH = -log₁₀21.6
pOH = -1.33
Since pH + pOH = 14
pH = 14 - (-1.33) = 15.33