Titrations

Question 1

What is the equation for concentration?

Answer 1

c = n / v

Question 2

What is the equation for dilution?

Answer 2

C1 V1 = C2 V2

Question 3

What are the quantities involved in the equation C1 V1 = C2 V2?

Answer 3

C1 = Stock solution conc
C2 = Desired conc
V1 = Volume of stock solution to use
V2 = Final volume

Question 4

What is the method for making up a standard solution?

Answer 4

1 - Take weighting boat and place on balance, tare balance and carefully weigh out required mass.

2 - Transfer to beaker and add water to dissolve, use some water to rinse all substance off weighing boat, at least twice.

3 - Stir with glass rod until dissolved, then transfer to volumetric flask using filter funnel, rinse beaker and glass rod, at least twice.

4 - Add water just below line on volumetric flask, add final drops with teat pipette to ensure bottom of meniscus is on line.

5 - Put lid on and turn over couple of times to mix solution.

Question 5

What are the acceptable colour changes for methyl-orange during a titration?

Answer 5

Acid - red / pink
Alkali - yellow

Question 6

What is methyl-orange suitable for in a titration?

Answer 6

Strong acid - strong base
Strong acid - weak base

Question 7

What are the acceptable colour changes for phenolphthalein during a titration?

Answer 7

Acid - colourless
Alkali - pink / red

Question 8

What is phenolphthalein suitable for in a titration?

Answer 8

Strong acid - strong base
Weak acid - strong base