Question

1. If it takes 67 mL of 0.15 M NaOH to neutralize 134 mL of an HCl solution, what is the concentration of the HCl?

2. If it takes 27.4 mL of 0.050 M H2SO4 to neutralize 357 mL of KOH solution, what is the concentration of the KOH solution?

3. If it takes 55 mL of 0.5 M NaOH solution to completely neutralize 130 mL of sulfuric acid solution (H2SO4), what is the concentration of the H2SO4 solution?

Answer 1

Answer:

The answer to your question is 1) 0.0075  2) 0.0077   3) 0.0105

Explanation:

1.-

Chemical reaction

               NaOH + HCl  ⇒    NaCl   +   H₂O

Calculate the moles of reactants

Molarity = moles / volume

moles = molarity x volume

moles = 0.15 x 0.067

          = 0.001005 moles of NaOH

               1 moles of NaOH ---------------- 1 moles of HCl

               0.001005 moles  ----------------  x

                x = (0.001005 x 1)/ 1 = 0.001005 moles of HCl

Concentration of HCl = 0.001005/0.134

                                   = 0.0075 M

2)

Chemical reaction

         H₂SO₄   +   2KOH  ⇒   K₂SO₄  +  2H₂O

Calculate the moles of H₂SO₄

moles = molarity x volume

moles = 0.05 x 0.0274

moles = 0.00137

        1 mol of H₂SO₄ ------------------ 2 moles of KOH

        0.00137            ------------------  x

         x = (0.00137 x 2) / 1

         x = 0.00274 moles

Calculate the molarity

Molarity = 0.00274/0.357

Molarity = 0.0077

3)

Chemical reaction

      2NaOH  +   H₂SO₄   ⇒    Na₂SO₄   +   2H₂O

Calculate the moles of NaOH

moles = molarity x volume

moles = 0.5 x 0.055

          = 0.0275

         2 moles of NaOH -----------------  1 mol of H₂SO₄

          0.0275 moles      -----------------  x

           x = (0.0275 x 1)/2

           x = 0.01375 moles of H₂SO₄

Molarity = 0.01375/0.130

Molarity = 0.0105