Titrations

Question 1

What is the equation for concentration?

Answer 1

Concentration = moles / volume (dm3)

Question 2

What is the purpose of a a titration?

Answer 2

To find the volume of one solution required to react exactly with a given volume of a second solution

Question 3

What are concordant results?

Answer 3

Within +/- 0.1 of eachother

Question 4

How do you set out a titration table?

Answer 4

Final burette reading then initial burette reading and titre vertically with the 3 titres horizontally.

Question 5

What is the apparatus needed to prepare a standard solution?

Answer 5

Volumetric flask and stopper, same size beaker, wash bottle of deionised water, glass rod, funnel and crystals

Question 6

How do you prepare a standard solution?

Answer 6

1. Weigh bottle of crystals, then empty crystals into the beaker and re weigh bottle. Subtract mass of bottle from initial mass to get mass of crystals.
2. Rinse volumetric flask and stopper with deionised water so it’s clean.
3. Add half of the flask’s volume of deionised water to crystals and stir with rod.
4. Pour solution through funnel into volumetric flask.
5. Rinse the beaker and glass rod with a little deionised water and pour washing’s through funnel into the flask. Repeat twice more.
6. Fill volumetric flask up to the calibration line of the flask with deionised water until the bottom of the meniscus is on the line.
7. Insert the stopper and keep your thumb on top. The, invert the flask about 10 times allowing the air bubble to travel to the top each time to mix the solution

Question 7

How do you pipette a solution?

Answer 7

1. Rinse the conical flask with deionised water and drain them.
2. Half fill a beaker with your solution and label.
3. Rinse the volumetric pipette with 10cm of soda solution and discard to waste.
4. Accurately measure 10cm of solution into conical flask allowing adequate time for pipette to drain - DO NOT FORCE LAST DROP OUT - hold flask at an angle and touch tip of pipette against the bottom to allow drop to settle.

Question 8

How do you carry out a titration?

Answer 8

1. Add 3-4 drops of indicator to the solution in the flask.
2. Take an initial reading of burette and record the value in the results table
3. Carry out a rough titration and note the burette reading.
4. Repeat these steps until you get concordant results.

Question 9

What is a standard solution?

Answer 9

A solution of known concentration