Unknowns Flashcards
Solubility Test
Carboxylic acids(if small), phenols, amines, small organics, ketones (if small)
Cerium Test
Alcohols and Phenols
Ferric Test
Phenols and Esters
Tollens Test
Aldehydes
Nitrous Test
Amines
Ferrous Hydroxide Test
Nitro groups
Silver Nitrate Test
Alkyl halides
How can Aceton give a false positive test with a cerium test?
can often give a false positive when glassware is used that has just been washed with water and acetone because: acetone is a ketone that can leave residues that react wit DNP, forming a precipitate that mimics the presence of carbonyl compounds.
Solubility in Pure Water
Polar compounds: Small polar molecules, alcohols, amines, carboxylic acids
Ionic compounds: salts, and strong acids/bases
Solubility in 5% NaHCO3
Not water soluble at pH 7 but soluble in 5% sodium bicarbonate
Weak acids: Carboxylic acids and phenols (they react with bicarbonate to form soluble salts)
Solubility in 1M NaOH
Soluble in strong base : NaOH
Phenols
some amines
Solubility in 6M HCl
Soluble in acid (HCl)
Bases: Amines
Carboxylic acids : Soluble things
Pure water: depends on size . if long, then int prevents the compound from mixing with water.
5% NaHCo3: soluble
1M NaOH : soluble
6M HCl: Generally soluble .. small carboxylic acids are soluble.
Carboxylic Acids: insoluble things
long chains in pure water
Esters: Soluble things
Pure water: small esters might..
Esters: insoluble things
5% NaHCO3
1M NaOH
6M HCl
Alcohols: soluble things
Pure water : only if its small
Alcohols: insoluble things
5% NaHCO3
1M NaOH
6M HCl
Phenols: Soluble things
Water: slightly
5% NaHCO3: Soluble
1M NaOH : Soluble
Phenols: insoluble things
6M HCl: insoluble
Amines: Soluble things
Water: Only if small
6M HCl: soluble
Amines: insoluble things
5% NaHCO3: insoluble
1M HaOH: Insoluble
Aldehydes: Soluble things
Pure water: only if small
Aldehydes: Insoluble things
5% NaHCO3: insoluble
1M NaOH: insoluble
6M NaOH: insoluble
Ketone: soluble things
Pure water: only if small
Ketone: Insoluble things
5% NaHCO3: insoluble
1M NaOH: insoluble
6M NaOH: insoluble
Amines - at what condition is it soluble?
Soluble under acidic conditions
Why phenol become soluble in 1M naoH ?
Phenols are more acidic than alcohols, since the phenoxide has resonance the alkoxide doesn’t.
Briefly explain why the cerium test is ambiguous for especially large alcohols.
If the large alcohol isn’t soluble in water, then it won’t be able to form a complex with cerium so will give a false negative result.
