Solubilities, flame tests and functional group tests

What is observed when magnesium ions react with sulfate ions?

no precipitate observed

What is observed when magnesium ions react with hydroxide ions?

white precipitate

What is observed when magnesium ions react with carbonate ions?

white precipitate

What is observed when barium ions react with sulfate ions?

thick/heavy white precipitate

What is observed when barium ions react with hydroxide ions?

no precipitate observed

What is observed when barium ions react with carbonate ions?

white precipitate

What is observed when calcium ions react with sulfate ions?

faint white precipitate

What is observed when calcium ions react with hydroxide ions?

faint white precipitate

What is observed when calcium ions react with carbonate ions?

white precipitate

What happens to the solubilities of group 2 sulfates down the group?

they decrease

What happens to the solubilities of group 2 hydroxides down the group?

they increase

What is the solubility of metal nitrates?

all soluble

What is the solubility of group 1 sulfates, hydroxides, carbonates and halides?

soluble

What is the solubility of group 2 halides?

soluble

What is colour precipitate is observed when AgNO₃ is added to Cl- ions? Does this dissolve in dilute NH₃? Does this dissolve in concentrated NH₃?

* white ppt
* dissolves in dilute NH₃
* dissolves in concentrated NH₃

What is colour precipitate is observed when AgNO₃ is added to Br- ions? Does this dissolve in dilute NH₃? Does this dissolve in concentrated NH₃?

* cream ppt
* insoluble in dilute NH₃
* dissolves in concentrated NH₃

What is colour precipitate is observed when AgNO₃ is added to I- ions? Does this dissolve in dilute NH₃? Does this dissolve in concentrated NH₃?

* yellow ppt
* insoluble in dilute NH₃
* insoluble in concentrated NH₃

What is the flame test colour for Li⁺?

red

What is the flame test colour for Na⁺?

yellow/yellow-orange

What is the flame test colour for Mg²⁺?

colourless

What is the flame test colour for Sr²⁺?

crimson

What is the flame test colour for Ba²⁺?

apple green

What is the flame test colour for Ca²⁺?

brick-red/orange

What is the flame test colour for K⁺?

lilac

What does FeCl₃ test for and what is observed as a positive result?

* phenols
* colour change to purple solution

What does bromine water test for and what is observed as a positive result?

* alkenes
* colour change from brown to colourless
* phenols
* white precipitate formed

What is a test used to identify carboxylic acids and what is observed?

* add a carbonate (Na₂CO₃)
* effervescence observed (CO₂)

What is 2,4-DNPH used to test for and what is observed when it is positive?

* aldehydes and ketones
* orange crystalline precipitate

What are the reagents for the triiodomethane test, what does it test for and what is observed when it tests positive?

* I₂ in NaOH
* tests for methyl groups in aldehydes and ketones and primary and secondary alcohols
* yellow precipitate observed

What is Tollen’s reagent used to test for and what is observed for a positive test?

* aldehydes
* silver mirror

What is Fehling’s solution used to test for and what is observed for a positive test?

* aldehydes
* brick red precipitate formed

What is used to test for an amine? What is observed if an amine is present?

* cold HONO (

What is used to test for the presence of thiosulfate ions? What is observed if the test is positive? How could this test be altered to test for the presence of a different compound?

* iodine
* solution turns from brown to colourless
* could add thiosulfate to iodine to test for iodine (also brown to colourless)

What is tested for using acidified potassium dichromate and what is the colour change observed?

* primary or secondary alcohols and aldehydes
* orange → green

What is tested for using acidified potassium manganate and what is the colour change observed?

* primary or secondary alcohols and aldehydes
* purple → colourless