titrations general

Question 1

indicator and colour change involved in water of crystallisation titration

Answer 1

methyl orange
orange –> permanent pink

Question 2

why is sodium hydroxide not a suitable primary standard

Answer 2

not stable and difficult to maintain in pure form

Question 3

Standard solution

Answer 3

a solution of accurately known concentration

Question 4

examples of primary standards

Answer 4

anhydrous sodium carbonate

ammonium iron (II) sulphate

Question 5

how is a standard solution prepared

Answer 5

dissolving an exact mass of a solute in a solvent, producing a definite volume of a solution

Question 6

primary standard

Answer 6

a substance which can be obtained in a pure, soluble stable and solid form so that it can be easily weighed out to make a solution of accurately known concentration.

Question 7

what indicator is used in the ethanoic acid titration and what is the colour change observed

Answer 7

phenolphthalein
pink –> colourless

Question 7

in what type of titrations is methyl orange used in

Answer 7

strong acid weak base

Question 8

what is a use of washing soda crystals

Answer 8

cleaning agent - tiles, drains, sinks and farmyard equipment
softens hard water by replacing the Mg2+ or Ca2+ ions with Na+ ions

Question 9

is methyl orange an acid or base (strong or weak)

Answer 9

weak acid

Question 10

what type is titrations is starch used in and what is the colour change observed

Answer 10

iodine titrations
blue/black to colourless

Question 11

what type of titrations is phenolphthalein used in

Answer 11

weak acid strong base

Question 12

physical properties of anhydrous sodium carbonate

Answer 12

white powder
anhydrous

Question 13

what does anhydrous mean

Answer 13

does not contain any water molecules

Question 14

what is a common answer for x in water of crystallisation

Answer 14

2 7 or 10

Question 15

what formula do you use when looking for the no of moles when taking a smaller volume from a solution made up in a volumetric flask

Answer 15

m x v divided 1000