Answer to Question #307651 in Chemistry for jack

Question

If a chemist titrates 450.0 mL of HBr with a 2.5 M solution of NaOH and requires only 2.2 mL of the base to reach the end point, what is the concentration of the hydrogen bromide?

Answer 1

Solution:

Balanced chemical equation:

HBr + NaOH → NaBr + H₂O

According to stoichiometry:

Moles of HBr = Moles of NaOH

Moles of solute = Molarity × Liters of solution

Therefore,

Molarity of HBr × Volume of HBr = Molarity of NaOH × Volume of NaOH

Molarity of HBr = (Molarity of NaOH × Volume of NaOH) / (Volume of HBr)

Molarity of HBr = (2.5 M × 2.2 mL) / (450.0 mL) = 0.012 M

Molarity of HBr = 0.012 M

Answer: The concentration of the hydrogen bromide (HBr) is 0.012 M