Making a standard solution

Question 1

What do you do when given a sample bottle containing the required mass of solid?

Answer 1

weigh on 2dp balance transfer to beaker and reweigh sample bottle record difference in mass

Question 2

What is a graduated flask?

Answer 2

volumetric flask

Question 3

What is a standard solution

Answer 3

solution containing a precisely known concentration of a solution

Question 4

How is the solution formed?

Answer 4

• add 100cm³ of distilled water to the beaker
  
  • use glass rod to stir to help dissolve the solid

Question 5

What is then done with the solution?

Answer 5

• pour solution into 250cm³ graduated flask via a funell
• rinse beaker and funnel and add washing from the beaker and glass rod to the volumetric flask
• make up to the mark with distilled water using a dropping pippette for the last few drops
  
  • for accuracy

Question 6

How is a uniform solution ensured?

Answer 6

invert the flask several times

Question 7

What happens in the substance is not dissolving well in cold water

Answer 7

gently heat until all the solid has dissolved

Question 8

Where should the meniscus lie

Answer 8

• bottom on the meniscus sits on the line on the neck of the flask

Question 9

What is the problems with dark liquids, such as potassium manganate

Answer 9

difficult to see the meniscus