NEET 2019 Chemistry Questions

Which of the following statements is not correct about diborane?

The number of sigma ($\sigma$) and pi ($\pi$) bonds in pent-2-en-4-yne is

Which of the following diatomic molecular species has only $\pi$ bonds according to Molecular Orbital Theory?

Match the Xenon compounds in Column-I with their structure in Column-II and assign the correct code: Column-I: (a) \ce{XeF4}, (b) \ce{XeF6}, (c) \ce{XeOF4}, (d) \ce{XeO3} Column-II: (i) pyramidal, (ii) square planar, (iii) distorted octahedral, (iv) square pyramidal

Which amongst the following is an incorrect statement?

Aluminium chloride in acidified aqueous solution forms a complex 'A', in which the hybridisation state of Al is 'B'. What are 'A' and 'B', respectively?

Which of the following is paramagnetic?

Which of the following is the correct order of dipole moment?

The number of hydrogen bonded water molecule(s) associated with \ce{CuSO4.5H2O} is:

The number of sigma ($\sigma$) and pi ($\pi$) bonds in pent-2-en-4-yne is

The most suitable reagent for the following conversion is: \ce{CH3-C#C-CH3 -> } cis-2-butene

Among the following, the reaction that proceeds through an electrophilic substitution is:

An alkene "A" on reaction with \ce{O3} and \ce{Zn-H2O} gives propanone and ethanal in equimolar ratio. Addition of \ce{HCl} to alkene "A" gives "B" as the major product. The structure of product "B" is:

The most stable carbocation among the following is:

The alkane that gives only one mono-chloro product on chlorination with \ce{Cl2} in presence of diffused sunlight is:

In the following reaction, \ce{H3C-C#CH} is passed through a red hot iron tube at $873\,\text{K}$ to give product $A$. The number of sigma ($\sigma$) bonds present in the product $A$ is:

The number of sigma ($\sigma$) and pi ($\pi$) bonds in pent-2-en-4-yne is

Among the following, the reaction that proceeds through an electrophilic substitution is:

The compound that is most difficult to protonate is:

The correct order of the basic strength of methyl-substituted amines in aqueous solution is:

The most stable carbocation among the following is:

The most stable carbocation among the following is:

Which of the following reactions are disproportionation reactions? (a) \ce{2Cu^+ -> Cu^2+ + Cu} (b) \ce{3MnO4^2- + 4H^+ -> 2MnO4^- + MnO2 + 2H2O} (c) \ce{2KMnO4 -> K2MnO4 + MnO2 + O2} (d) \ce{2MnO4^- + 3Mn^2+ + 2H2O -> 5MnO2 + 4H^+} Select the correct option from the following.

Which of the following oxoacids of phosphorus has the strongest reducing property?

When neutral or faintly alkaline \ce{KMnO4} is treated with potassium iodide, iodide ion is converted into 'X'. 'X' is

The oxidation state of \ce{Cr} in \ce{CrO5} is

The standard electrode potential ($E^\circ$) values of \ce{Al^3+/Al}, \ce{Ag+/Ag}, \ce{K+/K} and \ce{Cr^3+/Cr} are $-1.66$ V, $0.80$ V, $-2.93$ V and $-0.74$ V, respectively. The correct decreasing order of reducing power of the metals is

Under isothermal condition, a gas at $300\ \text{K}$ expands from $0.1\ \text{L}$ to $0.25\ \text{L}$ against a constant external pressure of $2\ \text{bar}$. The work done by the gas is (Given that $1\ \text{L\,bar} = 100\ \text{J}$)

For the cell reaction $\ce{2Fe^3+(aq) + 2I^-(aq) -> 2Fe^2+(aq) + I2(aq)}$, $E^\circ_{cell} = 0.24\ \text{V}$ at $298\ \text{K}$. The standard Gibbs energy ($\Delta_r G^\circ$) of the cell reaction is:

For a cell involving one electron, $E^\circ_{cell} = 0.59\ \text{V}$ at $298\ \text{K}$. The equilibrium constant for the cell reaction is: (Given that $\dfrac{2.303RT}{F} = 0.059\ \text{V}$ at $T = 298\ \text{K}$)

In which case is the change in entropy negative?

$4d$, $5p$, $5f$ and $6p$ orbitals are arranged in the order of decreasing energy. The correct option is:

Which of the following series of transitions in the spectrum of the hydrogen atom falls in the visible region?

An orbital having 3 angular nodes and 3 total nodes is:

In a hydrogen atom, the de Broglie wavelength of an electron in the second Bohr orbit is: [Given that Bohr radius $a_0 = 52.9$ pm]

For the second period elements the correct increasing order of first ionisation enthalpy is:

Match the oxide given in Column-A with its property given in Column-B: Column-A: (i) \ce{Na2O} (ii) \ce{Al2O3} (iii) \ce{N2O} (iv) \ce{Cl2O7} Column-B: (a) Neutral (b) Basic (c) Acidic (d) Amphoteric Which of the following options has all correct pairs?

The number of moles of hydrogen molecules required to produce 20 moles of ammonia through the Haber process is

The density of a 2 M aqueous solution of \ce{NaOH} is 1.28 g cm$^{-3}$. The molality of the solution is (molar mass of \ce{NaOH} = 40 g mol$^{-1}$)

Which of the following reactions are disproportionation reactions? (a) \ce{2Cu+ -> Cu^2+ + Cu} (b) \ce{3MnO4^2- + 4H+ -> 2MnO4^- + MnO2 + 2H2O} (c) \ce{2KMnO4 -> K2MnO4 + MnO2 + O2} (d) \ce{2MnO4^- + 3Mn^2+ + 2H2O -> 5MnO2 + 4H+} Select the correct option from the following:

The manganate (\ce{MnO4^2-}) and permanganate (\ce{MnO4^-}) ions are tetrahedral, due to:

Identify the incorrect statement.

Match the catalyst with the process: Catalyst (i) \ce{V2O5} (ii) \ce{TiCl4 + Al(CH3)3} (iii) \ce{PdCl2} (iv) Nickel complexes Process (a) The oxidation of ethyne to ethanal (b) Polymerisation of alkynes (c) Oxidation of \ce{SO2} in the manufacture of \ce{H2SO4} (d) Polymerisation of ethylene Which of the following is the correct option?

When neutral or faintly alkaline \ce{KMnO4} is treated with potassium iodide, iodide ion is converted into 'X'. 'X' is

The oxidation state of \ce{Cr} in \ce{CrO5} is:

The mixture that forms a maximum boiling azeotrope is:

For an ideal solution, the correct option is:

Which of the following statements is correct regarding a solution of two compounds A and B exhibiting positive deviation from ideal behaviour?

In water-saturated air the mole fraction of water vapour is 0.02. If the total pressure of the saturated air is 1.2 atm, the partial pressure of dry air is:

The density of a 2 M aqueous solution of \ce{NaOH} is $1.28\ \text{g/cm}^3$. The molality of the solution is [Given that molar mass of \ce{NaOH} $= 40\ \text{g mol}^{-1}$]:

The compound that is most difficult to protonate is:

The major product of the following reaction is: benzene-1,2-dicarboxylic acid (phthalic acid) \ce{->[{NH3}][{strong heating}]} ?

The reaction that does \textbf{not} give benzoic acid as the major product is:

When the vapours of a secondary alcohol are passed over heated copper at 573 K, the product formed is:

Which of the following statements is not correct?

Enzymes that utilize ATP in phosphate transfer require an alkaline earth metal (M) as the cofactor. M is:

The non-essential amino acid among the following is:

Which structure(s) of proteins remain(s) intact during the denaturation process?

The structure of intermediate A in the following reaction is: \ce{C6H5CH(CH3)2 + O2 -> A} \ce{A ->[H+/H2O] C6H5OH + CH3COCH3}

The reaction that does not give benzoic acid as the major product is:

When the vapours of a secondary alcohol are passed over heated copper at $573\,$K, the product formed is:

The major products C and D formed in the following reaction respectively are: \ce{H3C-CH2-CH2-O-C(CH3)3 + excess\ HI -> C + D}

For the cell reaction \ce{2Fe^3+(aq) + 2I-(aq) -> 2Fe^2+(aq) + I2(aq)}, $E^\circ_{cell} = 0.24$ V at $298$ K. The standard Gibbs energy ($\Delta_r G^\circ$) of the cell reaction is:

For a cell involving one electron $E^\circ_{cell} = 0.59$ V at $298$ K, the equilibrium constant for the cell reaction is: (Given that $\frac{2.303\,RT}{F} = 0.059$ V at $T = 298$ K)

Following limiting molar conductivities are given as $\Lambda_m^\circ(\ce{H2SO4}) = x\ \text{S cm}^2\,\text{mol}^{-1}$ $\Lambda_m^\circ(\ce{K2SO4}) = y\ \text{S cm}^2\,\text{mol}^{-1}$ $\Lambda_m^\circ(\ce{CH3COOK}) = z\ \text{S cm}^2\,\text{mol}^{-1}$ $\Lambda_m^\circ$ (in $\text{S cm}^2\,\text{mol}^{-1}$) for \ce{CH3COOH} will be :

The standard electrode potential ($E^\circ$) values of \ce{Al^3+/Al}, \ce{Ag+/Ag}, \ce{K+/K} and \ce{Cr^3+/Cr} are $-1.66\ \text{V}$, $0.80\ \text{V}$, $-2.93\ \text{V}$ and $-0.74\ \text{V}$, respectively. The correct decreasing order of the reducing power of the metals is:

If the rate constant for a first order reaction is $k$, the time $t$ required for the completion of 99% of the reaction is given by:

For the chemical reaction \ce{N2(g) + 3H2(g) <=> 2NH3(g)} the correct option is:

A first order reaction has a rate constant of $2.303\times10^{-3}\ \text{s}^{-1}$. The time required for $40\ \text{g}$ of this reactant to reduce to $10\ \text{g}$ will be (Given $\log_{10} 2 = 0.3010$):

For a reaction, the activation energy $E_a = 0$ and the rate constant at $200$ K is $1.6\times 10^{6}\ \text{s}^{-1}$. The rate constant at $400$ K will be (Given $R = 8.314\ \text{J K}^{-1}\text{mol}^{-1}$):

Among the following, the reaction that proceeds through an electrophilic substitution is:

An alkene A on reaction with $\ce{O3}$ then $\ce{Zn/H2O}$ gives propanone and ethanal in equimolar ratio. Addition of $\ce{HCl}$ to alkene A gives B as the major product. The structure of B is:

The hydrolysis reaction (with aq. NaOH) that takes place at the slowest rate, among the following, is :

What is the correct electronic configuration of the central atom in $\ce{K4[Fe(CN)6]}$ based on crystal field theory?

Aluminium chloride in acidified aqueous solution forms a complex 'A', in which the hybridisation state of Al is 'B'. What are 'A' and 'B', respectively?

The Crystal Field Stabilisation Energy (CFSE) for $\ce{[CoCl6]^4-}$ is $18000\ \text{cm}^{-1}$. The CFSE for $\ce{[CoCl4]^2-}$ will be:

The correct order of the basic strength of methyl-substituted amines in aqueous solution is:

The amine that reacts with Hinsberg's reagent to give an alkali-insoluble product is: