A 50.0 mL sample of hydrobromic acid, HBr, is titrated to an end point with 20.0 mL of 1.50 NaOH. What is the concentration of HBr?

The answer to your question is 0.6 M

Explanation:

Data

Volume of HBr = 50 ml

Volume of NaOH = 20 ml

[NaOH] = 1.5 M

[HBr] = ?

Process

1.- Calculate the moles of NaOH

Molarity = moles/volume

-Solve for moles

moles = Molarity x volume

-Substitution

moles = 1.5 x 0.02

-Result

moles = 0.03

2.- Write the balanced reaction

              HBr  +  NaOH  ⇒   NaBr  +  H₂O

3.- Calculate the moles of HBr

              1 moles HBr   1 moles NaOH

               x moles HBr   0.03 moles of NaOH

                         x = (0.03 x 1) / 1

                         x = 0.03 moles of HBr

4.- Calculate the concentration of HBr.

Molarity = 0.03 / 0.05

Molarity = 0.6 M

it is the most commonly accepted one