RP1 - Make up volumetric solution and carry out acid-base titration

Question 1

Define standard solution

Answer 1

A solution of a known concentration

Question 2

When choosing a solid to make a standard solution with, what 4 factors affects its suitability to be used to make a standard solution?

Answer 2

Whether it absorbs or loses moisture to environment

Has accurately known formula mass so moles can be calculated

Very pure

Has high formula mass to reduce weighing errors

Question 3

How do you prepare a standard solution?

Answer 3

Weigh mass of solid on balance in clean dry beaker
Dissolve solid in deionised water and stir with glass rod
Transfer solution into volumetric flask using a funnel
Wash beaker and stirring rod with deionised water into volumetric flask
Add deionised water to volumetric flask until bottom of the meniscus is in line with 250cm mark
Add a stopper and invert the flask

Question 4

What is the equation to find percentage error

Answer 4

(Uncertainty/ quantity measured) X100

Question 5

Process or carrying out a titration

Answer 5

Rinse burette with solution youre titrating with and discard
Rinse volumetric pippette with solution youre pipetting with and transfer 25cm^3 to conical flask
Add 2-3 drops of suitable indicator to conical flask
Use funnel to fill burette with solution and remove funnel and record initial volume
Add solution from burette with constant swirling until colour change for trial volume
Repeat titration to achieve 2-3 concordant results, adding solution dropwise near end point
Calculate mean titre

Question 6

Define concordant results

Answer 6

Results that are within 0.1cm^3 of each other