Chemical Changes RQP- determining reacting volumes of solutions of a strong acid and a strong alkali by titration

Question 1

what does this practical involve?

Answer 1

to make and record a range of measurements accurately, including volume of liquids. It also involves determining the concentration of one of the solutions in mol/dm3 and g/dm3

Question 2

what is the required apparatus (equipment) for this practical?

Answer 2

• burette
• pipette and filler
• conical flask and white tile

Question 3

what are the reagents for this practical? (chemicals)

Answer 3

• an acid (hydrochloric, sulfuric or nitric) of unknown concentration
• sodium hydroxide solution of known concentration
• a suitable indicator, for example methyl orange or phenolphthalein

Question 4

how would you draw the apparatus for this practical?

Answer 4

• a clamp stand with a white tile on the bottom
• flask with alkali and indicator on the white tile
• clamp stand clamping a biuret containing acid

Question 5

step 1

Answer 5

use the pipette and pipette filler to add 25 cm3 of alkali to a clean conical flask

Question 5

step 2

Answer 5

add a few drops of indicator and put the conical flask on a white tile

Question 6

step 3

Answer 6

fill the burette with acid and note the starting volume

Question 7

step 4

Answer 7

slowly add the acid from the burette drop by drop to the alkali in the conical flask, swirling to mix

Question 8

step 5

Answer 8

stop adding the acid when the end-point is reached (when the indicator first permanently changes colour) and then note the final volume reading

Question 9

step 6

Answer 9

repeat steps 1 to 5 until you get concordant titres