Look at the student's method for her experiment.

• Measure $25.0{cm}^3$ of $0.160{mol/dm}^3$ sodium hydroxide into a conical flask using a pipette.
• Add a few drops of universal indicator to the sodium hydroxide.
• Fill the burette to above the $0.00{cm}^3$ line with dilute sulfuric acid.
• Quickly add the dilute sulfuric acid to the sodium hydroxide until the indicator changes colour.
• Repeat the experiment.

Describe and explain one improvement the student should make to her method to get a more accurate titration result.

The student repeats the experiment four times.

Look at the student's results.

Calculate the accurate volume of the acid that reacts with the alkali.

Look at the equation for the reaction between sulfuric acid and sodium hydroxide.

$$H_2{SO}_4+2NaOH\to {Na}_2{SO}_4+2H_{2}O$$

Use your answer from part (b)(i) to calculate the concentration of the dilute sulfuric acid, $H_2{SO}_4$, that reacted with the $25.0{cm}^3$ of $0.160{mol/dm}^3$ sodium hydroxide.

Give your answer to 3 significant figures.