It is found that 24.68 mL of 0.1165 M NaOH is needed to titrate 0.2931 g of an unknown acid to the penolphtalein end point. Calculate the equivilent mass of the acid.
mL x N = (grams/equivalnt mass)
how do you find n (the number of ionizable protons)?
To calculate the equivalent mass of the acid, we need to use the equation:
Equivalent mass (g/mol) = Mass of acid (g) / Moles of acid
To determine the moles of acid, we can use the equation:
Moles of acid = Volume of NaOH (L) × Concentration of NaOH (mol/L)
First, let's convert the given volume of NaOH from mL to L:
Volume of NaOH (L) = 24.68 mL / 1000 mL/L = 0.02468 L
Next, we can calculate the moles of NaOH:
Moles of NaOH = Volume of NaOH (L) × Concentration of NaOH (mol/L) = 0.02468 L × 0.1165 mol/L = 0.002874 mol
Since NaOH and the acid react in a 1:1 ratio according to the balanced chemical equation, the moles of NaOH will also be equal to the moles of acid.
Now we can calculate the equivalent mass of the acid:
Equivalent mass of the acid (g/mol) = Mass of acid (g) / Moles of acid
= 0.2931 g / 0.002874 mol = 101.92 g/mol
Therefore, the equivalent mass of the acid is 101.92 g/mol.