* not completed

. Which of the following statements is false?

Chemical properties of Group 15 elements are uniform. correct incorrect

The Group 15 elements exhibit a wide range of oxidation states. correct incorrect

The Group 15 elements form many compounds with oxygen. correct incorrect

* not completed

. White and black phosphorus are __________ forms of the chemical element phosphorus.

isotopic correct incorrect

allotropic correct incorrect

polymorphic correct incorrect

* not completed

. Which of the following elements is used as a dopant in solid state devices?

Sb correct incorrect

As correct incorrect

P correct incorrect

* not completed

. Going down the group:

The +3 oxidation state becomes more favourable relative to the +5 one. correct incorrect

The +5 oxidation state becomes more favourable relative to the +3 one. correct incorrect

The +3 oxidation state predominates; the +5 one is rarely manifested. correct incorrect

* not completed

. The Haber process, which has had a major impact on civilization, produces:

hydrazine, N₂H₄ correct incorrect

ammonia, NH₃ correct incorrect

hydroxylamine, NH₂OH correct incorrect

* not completed

. PF₃ is a ligand that is similar to CO in that:

It is a weak σ-donor and a weak π-acceptor. correct incorrect

It is a strong σ-donor and a strong π-acceptor. correct incorrect

It is a weak σ-donor and a strong π-acceptor. correct incorrect

* not completed

. The synthetic procedures for the preparation of organophosphorus compounds very commonly start from:

PH₃ correct incorrect

PCl₃ correct incorrect

POCl₃ correct incorrect

* not completed

. NO is:

rapidly oxidized by O₂ to NO₂ in the atmosphere correct incorrect

a radical correct incorrect

not an atmospheric pollutant correct incorrect

* not completed

. When heated above 200ºC, phosphoric acid, H₃PO₄:

forms polyphosphates by condensation correct incorrect

decomposes thermally correct incorrect

explodes spontaneously correct incorrect

* not completed

. Select the correct answer:

Organometallic compounds of Group 15 elements in +3 oxidation state become less stable in the order Bi > Sb > As. Aryl compounds are more stable than alkyls. correct incorrect

Organometallic compounds of Group 15 elements in +3 oxidation state become less stable in the order As > Sb > Bi. Aryl compounds are more stable than alkyls. correct incorrect

Organometallic compounds of Group 15 elements in +3 oxidation state become less stable in the order As > Sb > Bi. Aryl compounds are less stable than alkyls. correct incorrect