Question: SO3 is not absorbed in water directly because__________________?

• 1. Reaction is exothermic
• 2. It is insoluble in water
• 3. Dilute acid is produced
• 4. All of above

Question: Which of the following will give phosphoric acid one reaction with water_________________?

• 1. PCI5
• 2. P2O3
• 3. P2O5
• 4. All of the above

Question: Phosphorus is a Greek word and it means_________________?

• 1. Light bearing
• 2. Fire
• 3. Impure
• 4. Tetrahedral

Question: Allotropic form of phosphorus that is poisonous is___________________?

• 1. White
• 2. Red
• 3. Black
• 4. Violet

Question: Acetic anhydride can be obtained by treating ethyl alcohol with___________________?

• 1. P2O5
• 2. H2SO4
• 3. Both A and B
• 4. PCI5

Question: Phosphorous acid upon thermal decomposition yields phosphoric acid and____________________?

• 1. Phosphine
• 2. Phosphorus
• 3. Water
• 4. Phosphorus pentoxide

Question: P2O5 is a hygroscopic powder which sublimes at______________?

• 1. 260°C
• 2. 360°C
• 3. 630°C
• 4. 620°C

Question: Phosphoric acid is a weak acid and its basicity is____________________?

• 1. 1
• 2. 3
• 3. zero
• 4. 2

Question: All the elements in group VIA are ___________________ in nature?

• 1. hygroscopic
• 2. metals
• 3. polymeric
• 4. all of above

Question: Which allotropic form of phosphorous is the most stable ?

• 1. White
• 2. black
• 3. red
• 4. Violet