Phosphorus Compounds

Question 1

White phosphorus

Colour, Feel, poisonous/non poisonous
Solubility in h20, and cs2
Chemiluminescent?
Stability
Reactivity
Flammablility
Formation of phosphine
Reaction with air

Answer 1

Translucent, white, waxy solid. Poisonous
Insoluble, soluble
Yes
Unstable
Highly reactive
Catches fire when exposed to air and gives dense white fumes of P4O10
P2 + NaOH + H2O–> PH3 + Na2H2PO2

Question 2

Red phosphorus

Prep
Colour, odour
Poisonous/non poisonous
Solubility in H2O and CS2
Chemiluminescent?

Answer 2

Heating white phosphorus in an inert atmosphere for several days.
Iron grey lusture, odourless
Non poisonous
Insoluble, insoluble
No

Question 3

Black phosphorus

Types
Prep of alpha
Sublimation or not
Str
Oxidizes in air?
Prep of beta
Burns in air upto 673K?

Answer 3

Alpha and ß
Red phosphorus heated in sealed tube at 803K
Yes
Monoclinic or rhombohedral
No
Heating white phosphorus at high pressure
No

Question 4

Phosphine

Prep
Prep in lab
Inflammatory
How to purify?

Answer 4

Ca3P2 with H2O or HCl
White phosphorus with naoh and h2O
Non inflammable when pure. Inflammable due to impurities P2H4 or P4 vap.
Absorbed in HI to form phosphonium iodide (PH4I)
On treating with KOH –> phosphine

Question 5

Phosphine

Colour, odour, poisonous/not
Reaction with oxidizing agents like HNO3 or Cl2 or Br2
Solubility in water
Decomposition in presence of light and h2o
Basic / acidic + reaction
Reaction with CuSO4 or HgCl2

Answer 5

Colourless, rotten fish like smell, highly poisonous
Explosive
Slightly soluble
Red phosphorus and H2
Weak base (PH3 + HBr –> PH4Br)
Respective phosphides

Question 6

PCl3

Prep with white phosphorus
Colour, feel
Hydrolysis?

Answer 6

P4 + dry Cl2 –> PCl3
P4 + SOCL2 –> PCl3 + SO2 + S2Cl2
Colourless, oily
Yes.. With water. Gives H3PO3 and HCl

Question 7

PCl5

Prep with white phosphorus
Colour, hydrolysis
Decomposition at higher and lower temp respectively.
Ag and Sn (finely divided)
Solid state

Answer 7

P4 + excess dry 10 Cl2
P4 + SO2Cl2 ( not SOCl2)
Yellowish white, gives POCl3 and later H3PO4
PCl3 (high temp. Low temp - sublimation)
AgCl and SnCl2
[PCl4]+[PCl6]-

Question 8

Oxoacids of Phosphorus

Reducing property

Answer 8

More no of P-H more reducing