Question

If you have 5.0 mL of a monoprotic acid with an unknown concentration and it requires 35.25 mL of 0.137M NaOH to reach the equivalence point in a titration, what is the concentration of the acid?

a) 0.0087 M

b) 0.0686 M

c) 0.0343 M

d) 0.137 M

Answer 1

The concentration of the monoprotic acid is calculated using the volume and molarity of the NaOH at the equivalence point. After identifying a discrepancy in the options provided, the calculations were rechecked, but no matches were found, suggesting a potential error in the provided data or options.

Step-by-step explanation:

To calculate the concentration of the monoprotic acid, we can use the titration data provided. Since the titration involves a monoprotic acid and NaOH, the reaction is a 1:1 mole ratio. Using the molarity (M) of NaOH and the volume (L) of NaOH used at the equivalence point, we can determine the moles of NaOH, which is equal to the moles of the acid, because of the 1:1 ratio.

First, calculate the moles of NaOH:

# moles NaOH = 0.03525 L * 0.137 M = 0.004829 mol NaOH

Since at the equivalence point, the moles of NaOH are equal to the moles of the acid, we can then calculate the concentration of the acid using its volume:

Concentration of acid = # moles acid / volume of acid in liters

Concentration of acid = 0.004829 mol / 0.005 L = 0.9658 M

Looking at the options provided, it seems like we need to check the calculations again, as none of the answer choices matches the calculation result. Note that such discrepancies might indicate a typo or misreading of the question data. Please double-check the values and calculations.