Question

A chemistry student weighs out of hypobromous acid into a volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with solution. Calculate the volume of solution the student will need to add to reach the equivalence point. Round your answer to significant digits.

Answer 1

See explanation below

Step-by-step explanation:

You are missing information in this exercise. I manage to find one, so I will use these data. If your data is different, just replace the data in this procedure, and follow the same procedure to get an accurate answer.

In this case, according to the picture attached we have 0.0669 g of Hypobromous acid (HBrO) reacting with 0.09 M of NaOH. Then, the acid base reaction in this case would be:

HBrO + NaOH ---------> NaBrO + H₂O

As we can see the reaction is already balanced and we can also watch that the mole ratio between the base and the acid is 1:1, therefore, we can use the following expression to calculate concentration or volume of solution to reach the equivalence point:

n₁ = n₂ (1)

and:

n = M * V (2)

Using these two expressions we can calculate the needed moles and then the volume.

We have the mass of the acid, which is 0.0669 g, the molecular mass of this acid reported is 96.91 g/mol, so the moles are:

n₁ = 0.0669 / 96.91 = 0.00069 moles

Now that we have the moles, we can say that the moles of this acid in the equivalence point are the same moles of the base used (Expression 1), so we can use (2) to calculate the required volume:

V = n/M

V = 0.00069 / 0.09

V = 7.67x10⁻³ L or simply 7.67 mL