Test: Class 12 Chemistry: CBSE Sample Question Paper- Term I (2021-22) - Class 12 MCQ

The structural formula of isobutyl alcohol is

IUPAC name : 2 methyl propan-1-ol

Phenoxide ion generated by treating phenol with sodium hydroxide. Further it undergoes electrophilic substitution with carbon dioxide to form ortho hydroxybenzoic acid as the main reaction product.

It is a method of preparation of glucose form sucrose i.e. cane sugar.

The other three are characteristics of isotropic solids.

Nitrogen does not form pentahalide due to non-availability of the d orbitals in its valence shell.

The others are the type of centred unit cell which have one or more constituent particles present at positions other than corners in addition to those at corners.

Chloroform mixed with nitrogen gas is an example of Liquid + gas solution.

It is a characteristic of globular protein.

The structure is -primary, quaternary, tertiary and secondary.

2-Chloro acetophenone is a substitute of acetophenone. It is phenacyl Chloride and use as a tear gas.

The colour is due to excitation of electrons (at anionic site) when they absorb energy from the visible light falling on the crystals.

Nitrogen oxides emitted from the exhaust systems of supersonic jet aeroplanes is slowly depleting the concentration of the ozone layer in the upper atmosphere as nitrogen oxides (particularly nitrogen monoxide) combine very rapidly with ozone.

Platinum (Pt) is an inert metal and does not react very easily. All other elements, Zn, Ti and Fe, are quite reactive.
Hence, Pt does not react with oxygen directly.

MnO is diamagnetic in nature.

3-bromopentane, due to presence of two same groups is not chiral. The central carbon is attached to two ethyl groups.

C₂H₅−CH(Br)−C₂H₅

All other compound contains chiral centre.

According to Raoult’s law, for any solution the partial vapour pressure of each volatile component in the solution is directly proportional to its mole fraction.

K₂SO₄ ionizes to give 2K⁺ and
SO₄ - ions (total 3 ions). NaCl gives Na⁺ and
Cl^- ions(total 2 ions) KCl gives K⁺ and Clions
(total 2 ions).

Sulphuric acid has strong affinity for water as moisture in gases that act as a strong dehydrating agent.

Asymmetric carbon atoms are those which have four different groups attached to carbon atom.

a = 268 pm = 268x10^-10 cm
d = 7.86 g cm^-3
M =56g m of^-1
NA = 6.022×10²³ mol^-1
n = ?

Fuming acid =HNO₃ + NO₂

∴ Electron density is highest at ortho and para positions, so, halogen atom (x) directs the incoming substituent in electrophilic substitution reaction to ortho and para positions.

Rhombic sulphur consists of 8 sulphur atoms arranged in an octahedral shape which form the most stable structure that doesn’t change gradually.

Both rhombic and mono clinic sulphur have S₈ molecules which is the most allotropic form.

SO₂(g) + H₂O(l) ⇋ H₂SO₃(l)

The given structure (i), (ii) and (iii) is showing Sulphurous acid, pyro sulphuric acid, sulphuric acid respectively.

Sulphuric acid have high boiling point and low volatility that combines with salt like NaCl to form volatile acids like HCl and HNO₃.