Analysis (testing for positive ions)

this shows the different ways you can test for negative and positive ions

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  • Created by: Ernie
  • Created on: 09-04-12 13:13

Positive Ions: Flame Test

Barium goes GREEN

Sodium goes YELLOW

Calcium goes ORANGE

Potassium goes PURPLE

Lithium goes RED

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Positive Ions (Sodium hydroxide)

Cu 2+ has a Blue Precipitate ( Cu 2+ (aq) + 2OH- (aq) = Cu(OH)2 (s) )

Fe 2+ has a Green Precipitate (goes orange in air)

Fe 3+ has a Orange Precipitate ( Fe 3+ (aq) + OH- (aq) = Fe(OH)3 (s) )

Al 3+ has a White Precipitate ( in excess NaOH, Al precipitate dissolves)

Mg 2+ has a White Precipitate

Ca 2+ has a White Precipitate

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Positive Ions : Ammonium

NH4+ + NaOH(warmed) = NH3

Test for NH3 is the smell and using red litmus paper goes blue as ammonium is alkaline.

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Bethany Cunningham


Straight to the point.

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