01 making solutions

Question 1

Practical One steps in fulls

Answer 1

1 – a) Making a standard solution
• Weigh the sample bottle containing the required mass of
solid on a 2 dp balance.
• Transfer to beaker and reweigh sample bottle.
• Record the difference in mass (this is called differential
weighing).
• Add 100cm3 of distilled water to the beaker. Use a glass
rod to stir to help dissolve the solid.
• Pour solution into a 250cm3
graduated flask via a funnel.
• Rinse beaker and funnel and add washings from the
beaker and glass rod to the volumetric flask.
• Make up to the mark with distilled water using a
dropping pipette for last few drops.
• Invert flask several times to ensure uniform solution.
Notes
• Sometimes the substance may not dissolve well in cold water so the beaker and its contents could be heated
gently until all the solid had dissolved.
• Remember to fill so the bottom of the meniscus sits on the line on the neck of the flask. With dark liquids
like potassium manganate it can be difficult to see the meniscus.

Question 2

steps 1 + 2

Answer 2

1 – a) Making a standard solution
• Weigh the sample bottle containing the required mass of
solid on a 2 dp balance.
• Transfer to beaker and reweigh sample bottle.

Question 3

step 3 + 4

Answer 3

• Record the difference in mass (this is called differential
weighing).
• Add 100cm3 of distilled water to the beaker. Use a glass
rod to stir to help dissolve the solid.

Question 4

step 5 / 6

Answer 4

• Pour solution into a 250cm3
graduated flask via a funnel.
• Rinse beaker and funnel and add washings from the
beaker and glass rod to the volumetric flask.

Question 5

step 7 / 8

Answer 5

• Make up to the mark with distilled water using a
dropping pipette for last few drops.
• Invert flask several times to ensure uniform solution.
Notes

Question 6

step 9 / 10

Answer 6

• Sometimes the substance may not dissolve well in cold water so the beaker and its contents could be heated
gently until all the solid had dissolved.
• Remember to fill so the bottom of the meniscus sits on the line on the neck of the flask.