moles 2

Question 1

how to convert from dm3 to cm3?

Answer 1

x1000

Question 1

how to convert from cm3 to dm3?

Answer 1

/1000

Question 2

how to calculate moles? (volume and 24)

Answer 2

moles= volume/24

Question 3

what is the concentration of a solution?

Answer 3

a measure of how much solute is dissolved per unit volume

Question 4

what is concentration measured in?

Answer 4

mol/dm3

Question 5

formula for concentration?

Answer 5

moles/volume

Question 6

formula for moles? (concentration and volume)

Answer 6

moles = concentration x volume

Question 7

what is titration used to measure?

Answer 7

the volume (titre) of acid needed to neutralise a particular volume of alkali

Question 8

what 2 pieces of equipment do you need for titration?

Answer 8

• volumetric pipette
• burette

Question 9

what does a volumetric pipette do?

Answer 9

• measures out 25cm3 very accurately

Question 10

what does a burette do?

Answer 10

measures any volume to the nearest 0.05cm3

Question 11

where does the acid and alkali go?

Answer 11

• acid goes into the burette
• alkali goes into the conical flask

Question 12

what is the setup for titration? (3 steps)

Answer 12

• use a volumetric pipette to place 25cm3 of the alkali into a conical flask
• add a few drops of methyl orange/ phenolphthalein to the conical flask
• fill a burette with a known acid and clamp it above the conical flask

Question 13

what is the usage of titration? (6 steps)

Answer 13

• measure the initial volume of the acid in the burette, to the nearest 0.05cm3
• use the burette to add acid into the conical flask drop-by-drop and keep swirling the conical flask
  -close the burette tap as soon as the conical flask changes colour
• measure the final volume of the known acid on the burette to the nearest 0.05cm3
• calculate titre (final volume- initial volume)
• repeat to get concordant values

Question 14

what will the start and end colour of titration be?

Answer 14

• start colour will be the alkaline
• end colour will be the acidic