Acid-Base: Concentration of Ethanoic acid in vinegar

Name the piece of apparatus used to measure accurately the 10cm³ portion of the original vinegar

Pipette

Describe how the pipette was rinsed before use

Rinsed with deionised water //

then rinsed with vinegar

Describe a suitable method to dilute the 10cm₃ portion of the vinegar to exactly 50.0cm³

Pipette 10cm³ of the original vinegar to a 50cm³ volumetric flask

Fill the volumetric flask to the graduation mark with deionised water

Add deionised water until the bottom of the meniscus is on the graduation mark

Stopper and invert 20 times

Outline an advantage of diluting the vinegar before carrying out the titration

Smaller % error

Name a suitable indicator for this titration. Justify your choice of indicator

Phenolphthalein

Weak acid - strong base / pH at end point passes through indicator range

[phenolphthalein range: 8-10]

State the colour change observed at the end point

Pink

to colourless