4NA - Salts

Question 1

what method is used to prepare SPA and other Group I salts?

Answer 1

titration

Question 2

what method is used to prepare insoluble salts?

Answer 2

precipitation

Question 3

what are the steps to obtain pure, dry crystals from a salt solution?

Answer 3

heat solution till saturation
cool to form crystals
filter to obtain crystals
wash crystals with small volume of cold, distilled water
dry crystals with filter paper

Question 4

why must be insoluble metal/base/carbonate be added in excess in the acid + excess insoluble reagent method of preparing soluble salts?

Answer 4

to use up all the acid.

[This ensures the aqueous salt can easily filtered out. If excess acid was present, the aqueous salt would be contaminated by the acid.]

Question 5

why must a titration be carried out twice - once with indicator, once without - in order to prepare a salt?

Answer 5

the first titration, with the indicator, is to determine the volumes of acid and alkali required.

the second titration, without the indicator, is to ensure the salt formed is pure and not contaiminated with indicator.

Question 6

all sulfates are soluble except ______________.

Answer 6

barium sulfate
calcium sulfate
lead(II) sulfate

Question 7

all chloride are soluble except ______________.

Answer 7

lead(II) chloride

silver chloride

Question 8

all ammonium salts are soluble. true or false?

Answer 8

true

Question 9

what method is used to prepare magnesium nitrate?

Answer 9

acid + excess insoluble metal/base/carbonate

Question 10

what are some suitable reactants to prepare lithium sulfate?

Answer 10

Lithium hydroxide or lithium carbonate
Dilute nitric acid

[SPA + Group I salts are prepared by titration. Reagents for titration are acid + alkali or acid + soluble carbonate]

Question 11

what are some suitable reactants to prepare barium sulfate?

Answer 11

barium nitrate or barium chloride
sodium sulfate or sulfuric acid

[barium sulfate is an insoluble salt and is prepared by precipitation. aqueous reagents are used in precipitation.]

Question 12

What acid can be used to make a chloride salt?

Answer 12

dilute hydrochloric acid

Question 13

What acid can be used to make a nitrate salt?

Answer 13

dilute nitric acid

Question 14

what alkali can be used to make potassium chloride?

Answer 14

potassium hydroxide

Question 15

why cant copper or silver or gold be used in the acid + excess insoluble reagent method?

Answer 15

copper, silver and gold are unreactive to acids.