Chemistry Test 82

HgI reacts with KI, to form K₂​[HgI₄​]. Due to this, the number of ions decreases thus decreasing the van't Hoff factor.

ΔTf​ = i × kf​ × m

Since ′i′ has decreased, it results in less depression in the freezing point causing the freezing point to rise.

Hence, the correct option is (A).

Glyptal, Buna S, Nylon 66, Dacron are copolymers because of the alternate chain.

A copolymer is a polymer derived from more than one species of monomer. The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained by copolymerization of two monomer species are sometimes called bipolymers.

Hence, the correct option is (A).

CO is used as a reducing agent. In the blast furnace, iron oxide is reduced by carbon.

Iron is extracted from ores by using a blast furnace. Iron is available for many ore forms some of them are at the temperature of 1300^oC, The carbon dioxide can be turned into carbon monoxide.

At the temperature of, 

And Carbon can be reduced from carbon monoxide.

Hence, the correct option is (C).

Minamata disease is a disorder caused by methyl mercury poisoning that was first described in the inhabitants of Minamata Bay, Japan and resulted from their eating fish contaminated with mercury industrial waste.

Hence, the correct option is (A).

The order of stability of carbocation can also be explained by assuming that alkyl groups bonded to a positively charged carbon release electron density toward that carbon and help delocalize the positive charge on the cation. Thereby, the electron releasing ability of alkyl groups bonded to a cationic carbon is considered by two effects, inductive effect, and hyper-conjugation.

S > R > Q > P > T is correct sequence
Hence, the correct option is (D).

The hexagonal crystal system consists of the 7 point groups that have a single six-fold rotation axis. These 7 point groups have 27 space groups (168 to 194), all of which are assigned to the hexagonal lattice system. Graphite ZnO and CdS is an example of a crystal that crystallizes in the hexagonal crystal system.

Hence, the correct option is (A).

Automobiles emissions contribute to air pollution and are a major ingredient in the creation of smog in some large cities. Transportation contributes to more than half of the carbon monoxide, sulphur dioxide and nitrogen oxides, and almost a quarter of the hydrocarbons emitted into our air. Carbon monoxide (CO) is a colourless, odourless, toxic non-irritating gas. It is a product of incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.

Hence, the correct option is (D).

The bond angle of H₂S (Hydrogen sulfide) is 90 degrees. The bond of the angle of NH₃ (Ammonia) is 107 degrees. The bond angle of BF₃ (Boron trifluoride) is 120 degrees. The bond angle of SiH₄ (Silicon hydride) is 109.5 degrees.

Hence, the correct option is (B).

The glycerine is used in excess amounts and hence obtained in products also. But when it is heated with Oxalic acid at 503K, it gives allyl alcohol, i.e. those alcohols in which OH group attached to carbon is sp3 hybridized but the sp3 hybridized carbon is attached to sp2 hybridized carbon atom.
Hence, the correct option is (C).

The molecular geometry of PCl₅ is trigonal bipyramid with symmetric electron region distribution around the central atom.

These are arranged in a trigonal bipyramidal shape with a 175° F(axial)-Cl-F(axial) bond angle. The two lone pairs take equatorial positions because they demand more space than the bonds. The result is a T-shaped molecule.
Hence, the correct option is (A).