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Question 1

Al3+

Answer 1

NaOH white ppt soluble in excess
NH3 white ppt insoluble

Question 2

Zn2+

Answer 2

NaOH white ppt soluble in excess
NH3 white ppt soluble in excess

Question 3

Ca2+

Answer 3

NaOH white ppt insoluble in excess
NH3 no ppt

Question 4

Fe2+

Answer 4

NaOH green ppt
NH3 green ppt
ppt turns red brown upon standing for ard 10mins

Question 5

Fe3+

Answer 5

NaOH red brown ppt
NH3 red brown ppt

Question 6

Cu2+

Answer 6

NaOH blue ppt
NH3 blue ppt, soluble in excess to form dark blue solution

Question 7

NH4_

Answer 7

NaOH no ppt, upon heating ammonia gas liberated
no NH3

Question 8

CO3 2-

Answer 8

add dilute acid, pass gas through lime water
effervescence observed
colourless odourless gas evolved
gas forms white ppt with limewater
CO2 evolved

Question 9

Cl-

Answer 9

add AgNO3(aq) and dilute nitric acid(acid ensure not carbonate)
white ppt formed
ppt insoluble in dilute acid

Question 10

I-

Answer 10

add AgNO3(aq), then dilute nitric acid (ensure not carbonate)
yellow ppt formed
ppt insoluble in dilute acid

Question 11

SO4 2-

Answer 11

add Ba(NO3)2(aq), then dilute acid (ensure not carbonate)
white ppt formed
ppt insoluble in dilute acid

Question 12

NO3 -

Answer 12

add NaOH(aq) then devarda’s alloy/aluminium, then warm gently
colourless pungent gas evolved
gas turns moist red litmus paper blue
NH3 evolved