Question

How many milliliters of 0.0850 M NaOH are required to titrate 25.0 mL of 0.0720 M hydrobromic acid, HBr, to the equivalence point?

Answer 1

21.2 mL

Step-by-step explanation:

Step 1: Write the balanced equation.

NaOH + HBr ⇒ NaBr + H₂O

Step 2: Calculate the reacting moles of HBr

25.0 mL of 0.0720 M hydrobromic acid react.

`0.0250 L * (0.0720mol)/(L) = 1.80 * 10^(-3) mol`

Step 3: Calculate the reacting moles of NaOH

The molar ratio of NaOH to HBr is 1:1. The reacting moles of NaOH are 1/1 × 1.80 × 10⁻³ mol = 1.80 × 10⁻³ mol.

Step 4: Calculate the required volume of NaOH

`1.80 * 10^(-3) mol *(1,000mL)/(0.0850mol) = 21.2 mL`