Ans. (c)
Ethanol and acetone do not form ideal solution because hydrogen bonding between ethanol molecules is weakened by acetone which leads to positive deviation from Raoult’s law.
Ans. (b)
When molten NaCl is doped with Sr2+, some of the Sr2+ ions occupy sites of Na+ ions creating vacancies of Na+ ions as each Sr2+ will replace two Na+ ions.
Ans. (d)
Ans. (a)
Ans. (b)
Hydroxyl group does not act as a good leaving group and does not displaced by a nucleophile. To facilitate the reaction, -OH group of alcohol is need to be protonated by an acid such as sulphuric acid.
Ans. (d)
Nucleotide forms DNA strand and each nucleotide is made by:
Ans. (b)
Stability of -3 oxidation state decreases down the group due to increase in size and metallic character.
Ans. (c)
Ans. (b)
NaBH4 is a weak reducing agent than LiAlH4. It reduces only ketone group in the given compound.
Ans. (a)
In case of negative deviation from Raoult’s law, new bonds formed between molecules are stronger than the intermolecular forces between respective constituents. The tendency of molecules to escape decrease and boiling point increases.
Ans. (c)
In the crystal of FeO, some Fe2+ ions are missing and for the loss of every three Fe2+ ions, two Fe3+ ions present causing metal deficiency.
Ans. (b)
Ans. (d)
Ans. (b)
Ans. (a)
Tertiary alcohols give turbidity immediately with Lucas reagent as they form halides easily.
Ans. (d)
In case of haloarenes, presence of an electron withdrawing group (such as -NO2) at ortho- and para- position increases their reactivity.
Ans. (d)
Solids and liquids are highly incompressible due to absence of intermolecular spaces.
Ans. (c)
Ans. (b)
Only nitrogen forms p—p multiple bonds due to small size and high electronegativity. Other elements of group-15 do not form p—p multiple bonds due to large and highly diffused atomic orbitals.
Ans.(a)
Fluorine (F) can replace all other halogens from their halide compound because of small size and high electronegativity.
Ans. (c)
Ans. (d)
In case of helium, only weak dispersion forces are present leading to low boiling point.
Ans. (a)
Ans. (b)
Ans. (d)
Ans. (c)
Ans. (a)
Ans. (c)
Ans. (c)
Ans. (d)
Ans.(c)
In vapour state of sulphur partly exists as S2 molecule and S2 molecule has two unpaired electrons in the anti-bonding orbitals.
Ans. (b)
Ans. (a)
Ans. (a)
HI is the strongest reducing agent among halogen acids because of lowest bond dissociation energy.
Ans. (a)
Ans. (b)
Ans. (c)
NO2 contains odd number of valance electrons. On dimerisation, it gives N2O4 molecule having even number of electrons.
Ans. (a)
Ans. (c)
PF5 act as a fluoride ion acceptor.
Ans. (b)
-NO2 is an electron withdrawing group and stabilises the phenoxide ion while -CH3 is an electron donating group and do not favours the phenoxide ion formation.
Ans. (d)
Ans. (b)
Among halide ions, iodine is the weakest oxidising agent due to its large size.
Ans. (d)
Ans. (b)
Ans. (d)
Ammonia (NH3) is more basic than PH3 as the size of nitrogen is smaller and electron density is more than phosphorous.
Ans. (a)
Ans. (c)
Aryl halides are extremely less reactive towards nucleophilic substitution reaction due to resonance effect.
Ans. (a)
Frenkel defect is also called as dislocation effect. The smaller ion (cation) is dislocated to an interstitial site and no change in density observed.
Ans. (c)
Ozone is a powerful oxidising agent as it liberates nascent oxygen easily. Ozone is thermodynamically unstable with respect to ozone and it produces heat by decomposing to oxygen
Ans. (c)
Ans. (b)
Oxygen contains no d-orbital for bonding.
Cl2 is less reactive than ClF.
Xe form many compounds but He not.
Ans. (d)
ZnS - Ionic solid (contains ionic bonds as zinc is metal and sulphur is a non-metal) SiC - Covalent solid (contains covalent bonds as both elements are non-metals)
Read the passage given below and answer the following question nos. 53 – 55.
Carbohydrates are polyhydroxy aldehydes or ketones and are also called saccharides. Glucose is an example of monosaccharides. Glucose (C6H12O6) is an aldohexose and its open chain structure was assigned on the basis of many reactions as evidences like presence of carbonyl group, presence of straight chain, presence of five -OH groups, etc. Glucose is correctly named as D-(+)-Glucose. Glucose is found to exist in two different crystalline forms which are named as and . Despite having the aldehyde group, glucose does not give 2, 4-DNP test.
Ans. (b)
Ans. (d)
Ans. (b)
Carbonyl group (>C=O) reacts with hydroxylamine (NH2OH) to form an oxime. No reaction with hydroxylamine confirms absence of carbonyl group in pentacetate of glucose.