Salt analysis 3

Question 1

NH4+ present

Answer 1

• Heat the given salt with NaOH.
  Smell of NH3
• Bring a glass rod dipped in Conc. HCl near a mouth of the test tube.
  Dense white fumes evolves

Question 2

NH4+ confirmed

Answer 2

• Add Nesslers reagent to the salt solution.
  Brown ppt formed

Question 3

CO32-
Present.

Answer 3

• Treat the salt with dil. H2SO4 solution
  Observation: -
• colourless and odourless gas with brisk effervescence evolve

Question 4

S2- present

Answer 4

• Treat the salt with dil. H2SO4 solution
  Observation: -
• Colourless gas with smell of rotten egg turning lead acetate paper black.

Question 5

Cl- present

Answer 5

• Treat with con. H2SO4 solution
  Observation: -
• Colourless gas with pungent smell giving dense white fumes with glass rod dipped in NH40H.

Question 6

Br- present

Answer 6

• Treat with con. H2SO4 solution
  Observation: -
• Reddish brown vapour and solution turns brown

Question 7

I- present

Answer 7

• Treat with con. H2SO4 solution
  Observation: -
• Violet vapour

Question 8

NO3- present

Answer 8

• Treat with con. H2SO4 solution
  Observation: -
• Reddish brown vapour obtained on heating

Question 9

Acetate present

Answer 9

• Treat with con. H2SO4 solution
  Observation: -
• Vinegar smell

Question 10

(2) NO3- present

Answer 10

• Treat with con. H2SO4 solution.
  Add Cu turning to the above solution(if Nitrate) and heat.
  Observation:-
• Intense brown vapour evolves and solution turns blue.