qualitive analysis

Question 1

test for carbonate

Answer 1

negative anion
-bubble gas through limewater to test for CO2
- if CO2 is detected it will turn cloudy

Question 2

testing for a sulphate

Answer 2

testing for negative anions
acidified BaCl2 is used to test for sulphate ions , if the solution contains sulphate ions a white precipice will form
-sulphuric acid cannot be used to test for sulphate ions because it already contains sulphate ions

Question 3

testing for halide ions

Answer 3

use nitric acid then silver nitrate solution
fluorine-no precipitate
chlorine-white precipitate
bromine- cream precipitate
iodine- pale yellow precipitate
the role of nitric acid is to react any carbonates to prevent formation of the precipitate Ag2CO3

Question 4

ammonia solution

Answer 4

you can use ammonia solution to differentiate if the colours look similar
silver chlorine - dilute ammonia
silver bromide - concentrated ammonia
silver iodide - does not react with ammonia , its too insoluble

Question 5

sequence of tests

Answer 5

carbonate
sulphate
halide

Question 6

testing for positive ions ( cations )

Answer 6

test for ammonium NH4+
warm NaOH(aq) forming NH3 gas

ammonia gas can be identified by its smell or by turning red litmus paper blue