Chapter 6 Chemical equations - tests for anions

Question 1

exothermic reaction

Answer 1

gives of heat

Question 2

endothermic reaction

Answer 2

takes in heat

Question 3

Anion = chloride (test, observation,)

Answer 3

add a few drops of AgNO3 sol. to a sol. of the solid , white precipitate is formed which is soluble in dilute ammonia sol. ,

Question 4

Anion = Sulfate/sulfite (test, observation)

Answer 4

Add BaCl2 sol. to a sol of the solid ,distinguishing test = add dilute HCl , A white precipitate is formed (if remain=sulfate , if dissolves= sulfite ,

Question 5

Anion = Carbonate/hydrogen carbonate (test, observation)

Answer 5

Add dilute HCl to the solid (fizzing , a gas is given off that turns limewater milky) Distinguishing test = add MgSO4 to a fresh sol. of the solid ( white precipitate forms , carbonate=no precipitate , hydrocarbonate = boiling gives a precipitate

Question 6

Anion = Nitrate (test, observation)

Answer 6

Brown ring test, to a sol. of solid add FeSO4 sol. + add concentrated sulphuric acid , brown ring is formed at the junction of the 2 liquids .’. nitrate ion present

Question 7

Anion= Phosphate (test, observation)

Answer 7

Ammonium molybdate is added to a sol. of the solid concentrated nitric acid is added , sol. is warmed , Yellow precipitate is formed .’. Phosphate ions are present