Ch 2p-Block Elements (Groups 15-18) — Class 12 Chemistry, concept-first.

Groups 15 through 18 close out the p-block of the periodic table. Group 15, the nitrogen family (N, P, As, Sb, Bi), has the general valence configuration ; Group 16, the oxygen family (O, S, Se, Te, P…

Group 15, the nitrogen family, comprises nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb) and bismuth (Bi), all sharing the general outer-shell configuration -- a half-filled p sub-shell, whi…

Ammonia, , is by far the most important hydride of nitrogen. Structurally, the nitrogen atom is hybridised: three of its four hybrid orbitals form bonds to the three hydrogen atoms, and the fourth hol…

Nitric acid, , is manufactured on an industrial scale from ammonia by the Ostwald process, a three-stage catalytic oxidation.

Nitrogen trichloride, , is prepared by passing chlorine gas over ammonia in large excess, or by the chlorination of an ammonium salt solution; if the ammonia is not kept in large excess the product ca…

Phosphorus, unlike nitrogen, shows extensive allotropy -- it exists in several distinct structural forms, of which white phosphorus and red phosphorus are the two prescribed here for detailed comparis…

Phosphine, , is the phosphorus analogue of ammonia and, like , is manufactured and studied mainly as a laboratory reagent rather than a bulk industrial chemical.

Phosphorus forms two particularly important chlorides, and , illustrating the group's characteristic oxidation-state pair and, in 's case, phosphorus's ability to expand its valence shell beyond an oc…

Phosphorus forms a family of oxoacids that differ systematically in their basicity (how many protons they can donate) and in whether they act as reducing agents -- and both properties follow directly…

Group 16, the oxygen family, comprises oxygen (O), sulphur (S), selenium (Se), tellurium (Te) and polonium (Po), sharing the general outer configuration -- two electrons short of a complete octet, whi…

Ozone, , is the triatomic allotrope of oxygen and, along with ordinary diatomic dioxygen, one of only two allotropes of the element studied at this level.

Sulphur, like phosphorus, shows extensive allotropy, and the two crystalline forms prescribed for detailed study here -- rhombic (-) sulphur and monoclinic (-) sulphur -- are an instructive case of tw…

Sulphur forms two industrially crucial gaseous oxides. Sulphur dioxide, , is obtained by burning sulphur (or iron pyrites, ) in air or oxygen, or in the laboratory by treating a sulphite with dilute s…

Group 17, the halogens, comprises fluorine (F), chlorine (Cl), bromine (Br), iodine (I) and the rare, intensely radioactive astatine (At), sharing the general outer configuration -- just one electron…

Chlorine, bromine and iodine form a range of oxides, most of which are unstable, powerfully oxidising, and (in several cases) explosively decompose.

Interhalogen compounds are formed by the direct combination of two different halogens, and fall into four general structural families, written , , and , where is the larger, less electronegative halog…

Group 18, the noble gases, comprises helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and the radioactive radon (Rn).

For a very long time the noble gases were believed to be entirely, categorically unreactive -- hence the older name "inert gases" -- until 1962, when Neil Bartlett showed that xenon could indeed be ma…

Sample papers and previous-year board questions for this subject.