A. Write an equation for determining the number of moles of NaOH that are added to the flask based on [NaOH] and volume of NaOH titrant (mL NaOH):

B. Write a similar expression for the number of moles of H2SO4 in the flask based on [H2SO4] and the volume of H2SO4 (mL).

Substitute your expressions from A and B into this equation and solve for [H2SO4]

From the equation for molarity (number of moles of a substance dissolved in one liter of solution), we can get an equation for determining the number of moles:

c=n/V ⇒ n=c*V

Now, we can write required equations:

A n (NaOH) = c (NaOH) * V (NaOH)

B n (H₂SO₄) = c (H₂SO₄) * V (H₂SO₄)

From the reaction, we can conclude that NaOH and H₂SO₄ have following stoichiometric ratio:

2NaOH + H₂SO₄ ⇒ Na₂SO₄ + 2H₂0

n (NaOH) : n (H₂SO₄) = 2 : 1

So, we can write:

n (NaOH) = 2 * n (H₂SO₄)

And if we connect the above equations, we get the equation for solving c (H2SO4):

c (NaOH) * V (NaOH) = 2*c (H₂SO₄) * V (H₂SO₄)

c (H₂SO₄) = (c (NaOH) * V (NaOH)) / (2*V (H₂SO₄))