JEE Mains JEE Advance BITSAT
JEE Mains | PYQ

Chemistry

The nature of oxides \( \mathrm{V_2O_3} \) and \( \mathrm{CrO} \) is indexed as 'X' and 'Y' type respectively. The correct set of X and Y is:

In the following sequence of reactions the P is:

Given below are two statement: one is labelled as Assertion (A) and the other is labelled as Reason(R).
Assertion (A): Synthesis of ethyl phenyl ether may be achieved by Williamson synthesis.
Reason (R): Reaction of bromobenzene with sodium ethoxide yields ethyl phenyl ether.
In the light of the above statements, choose the most appropriate answer from the options given below:

The number of water molecules is gypsum, dead burnt plaster and plaster of Paris, respectively are:

The gas 'A' is having very low reactivity reaches to stratosphere. It is non-toxic and non-flammable but dissociated by UV-radiations in stratosphere. The intermediates formed initially from the gas 'A' are:

Which refining process is generally used in the purification of low melting metals?

The unit of the van der Waals gas equation parameter ‘a’ in \( \left(P+\frac{a n^{2}}{V^{2}}\right)(V-nb)=nRT \) is:

In the following sequence of reactions, the final product \( D \) is:

In which one of the following molecules strongest back donation of an electron pair from halide to boron is expected?

Deuterium resembles hydrogen in properties but:

Acidic ferric chloride solution on treatment with excess of potassium ferrocyanide gives a Prussian blue coloured colloidal species. It is:

The correct statement about \( (A) \), \( (B) \), \( (C) \) and \( (D) \) is:

Tyndall effect is more effectively shown by:

The major product of the following reaction is:

Which of the following is not a correct statement for primary aliphatic amines?

Out of following isomeric forms of uracil, which one is present in RNA?

The structure of the starting compound P used in the reaction given below is:

Match items of List-I with those of List-II:

Choose the most appropriate answer from the options given below:

In polythionic acid, \({H_2S_xO_6} \) (\( x = 3 \) to \( 5 \)) the oxidation state(s) of sulphur is/are:

Match List-I with List-II:

Choose the most appropriate answer from the options given below:

The number of \( f \) electrons in the ground state electronic configuration of \( \mathrm{Np} \) (\( Z = 93 \)) is __________. (Integer answer)

The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is equal to \( \dfrac{h^{2}}{x m a_{0}^{2}} \). The value of \( 10x \) is __________. (\( a_{0} \) is radius of Bohr’s orbit) (Nearest integer) [Given: \( \pi = 3.14 \)]

The number of moles of \( \mathrm{CuO} \), that will be utilized in Dumas method for estimating nitrogen in a sample of \( 57.5 \,\text{g} \) of \( \mathrm{N,N} \)-dimethylaminopentane is __________ \( \times 10^{-2} \). (Nearest integer)

In Carius method for estimation of halogens \( 0.2 \,\text{g} \) of an organic compound gave \( 0.188 \,\text{g} \) of \( \mathrm{AgBr} \). The percentage of bromine in the compound is __________. (Nearest integer) [Atomic mass: \( \mathrm{Ag} = 108 \), \( \mathrm{Br} = 80 \)]

When \( 10 \, \text{mL} \) of an aqueous solution of \( \mathrm{KMnO_4} \) was titrated in acidic medium, equal volume of \( 0.1 \, \text{M} \) of an aqueous solution of ferrous sulphate was required for complete discharge of colour. The strength of \( \mathrm{KMnO_4} \) in grams per litre is __________ \( \times 10^{-2} \). (Nearest integer)
[Atomic mass of \( \mathrm{K} = 39 \), \( \mathrm{Mn} = 55 \), \( \mathrm{O} = 16 \)]

The number of moles of \( \mathrm{NH_3} \), that must be added to \( 2 \, \text{L} \) of \( 0.80 \, \text{M} \) \( \mathrm{AgNO_3} \) in order to reduce the concentration of \( \mathrm{Ag^+} \) ions to \( 5.0 \times 10^{-8} \, \text{M} \) \( (K_{\text{formation}} \text{ for } [\mathrm{Ag(NH_3)_2}]^{+} = 1.0 \times 10^{8}) \) is __________. (Nearest integer)
[Assume no volume change on adding \( \mathrm{NH_3} \)]

\( 1 \) mol of an octahedral metal complex with formula \( \mathrm{MCl_3 \cdot 2L} \) on reaction with excess of \( \mathrm{AgNO_3} \) gives \( 1 \) mol of \( \mathrm{AgCl} \). The denticity of Ligand \( \mathrm{L} \) is __________. (Integer answer)

\( 1 \, \text{kg} \) of \( 0.75 \) molal aqueous solution of sucrose can be cooled up to \( -4^\circ \text{C} \) before freezing. The amount of ice (in \( \text{g} \)) that will be separated out is ______________. (Nearest integer)
[Given: \( K_f(\mathrm{H_2O}) = 1.86 \, \text{K} \, \text{kg} \, \text{mol}^{-1} \)]

The reaction that occurs in a breath analyser, a device used to determine the alcohol level in a person's blood stream is:
\( 2\mathrm{K_2Cr_2O_7} + 8\mathrm{H_2SO_4} + 3\mathrm{C_2H_6O} \rightarrow 2\mathrm{Cr_2(SO_4)_3} + 3\mathrm{C_2H_4O_2} + 2\mathrm{K_2SO_4} + 11\mathrm{H_2O} \)
If the rate of appearance of \( \mathrm{Cr_2(SO_4)_3} \) is \( 2.67 \, \text{mol} \, \text{min}^{-1} \) at a particular time, the rate of disappearance of \( \mathrm{C_2H_6O} \) at the same time is ____________ \( \text{mol} \, \text{min}^{-1} \). (Nearest integer)

\( 200 \, \text{mL} \) of \( 0.2 \, \text{M} \) \( \mathrm{HCl} \) is mixed with \( 300 \, \text{mL} \) of \( 0.1 \, \text{M} \) \( \mathrm{NaOH} \). The molar heat of neutralization of this reaction is \( -57.1 \, \text{kJ} \). The increase in temperature in \( ^\circ \text{C} \) of the system on mixing is \( x \times 10^{-2} \). The value of \( x \) is ____________ (Nearest integer)
[Given: Specific heat of water \( = 4.18 \, \text{J} \, \text{g}^{-1} \text{K}^{-1} \), Density of water \( = 1.00 \, \text{g} \, \text{cm}^{-3} \)]
(Assume no volume change on mixing)

JEE Main 2021 27th August Morning Shift

Physics Chemistry Mathematics

← PreviousQuestion 39 of 90Next →

In which one of the following molecules strongest back donation of an electron pair from halide to boron is expected?