NEET 2018 Chemistry Questions

The correct order of N-compounds in its decreasing order of oxidation states is

Which one of the following elements is unable to form $\ce{MF6^3-}$ ion?

The correct order of atomic radii in group 13 elements is

Which of the following oxides is most acidic in nature?

Among $\ce{CaH2}, \ce{BeH2}, \ce{BaH2}$, the order of ionic character is

Magnesium reacts with an element ($X$) to form an ionic compound. If the ground state electronic configuration of ($X$) is $1s^2\,2s^2\,2p^3$, the simplest formula for this compound is

Which one of the following elements is unable to form \ce{MF6^3-} ion?

In the structure of \ce{ClF3}, the number of lone pairs of electrons on the central atom Cl is:

Which of the following molecules represents the order of hybridisation $sp^2$, $sp^2$, $sp$, $sp$ from left to right atoms?

Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. This is due to their:

Consider the following species: \ce{CN^+}, \ce{CN^-}, \ce{NO} and \ce{CN}. Which of these will have the highest bond order?

In which of the following molecules is the order of hybridisation $sp^2$, $sp^2$, $sp$, $sp$ for the carbon atoms from left to right?

Which of the following carbocations is expected to be the most stable? (Each is a cyclohexadienyl-type cation bearing an \ce{-NO2} substituent on the ring, with the positive charge located at varying ring positions relative to the \ce{-NO2} group.)

Which of the following is correct with respect to the $-I$ effect of the substituents? (R = alkyl)

In the Reimer-Tiemann reaction, \ce{C6H5-O^- Na^+ + CHCl3 + NaOH -> } salicylaldehyde (o-hydroxybenzaldehyde), the electrophile involved is:

The correct order of N-compounds in their decreasing order of oxidation states is

Consider the change in oxidation state of bromine corresponding to different $E^\circ$ values as shown in the Latimer diagram below: \ce{BrO4^-} $\xrightarrow{1.82\,\text{V}}$ \ce{BrO3^-} $\xrightarrow{1.5\,\text{V}}$ \ce{HBrO} $\xrightarrow{1.595\,\text{V}}$ \ce{Br2} $\xrightarrow{1.0652\,\text{V}}$ \ce{Br^-} Then the species undergoing disproportionation is

For the redox reaction \ce{MnO4^- + C2O4^2- + H^+ -> Mn^2+ + CO2 + H2O}, the correct coefficients of the reactants for the balanced equation are (\ce{MnO4^-}, \ce{C2O4^2-}, \ce{H^+} respectively)

The compound \ce{C7H8} (toluene) undergoes the following reactions: \ce{C7H8 ->[3Cl2,\ \Delta] A ->[Br2/Fe] B ->[Zn/HCl] C} The product 'C' is

Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which, by Wurtz reaction, is converted to a gaseous hydrocarbon containing less than four carbon atoms. (A) is

Which of the following molecules represents the order of hybridisation $sp^2, sp^2, sp, sp$ from left to right atoms?

Which one is the wrong statement?

Which one is a wrong statement?

Magnesium reacts with an element \ce{X} to form an ionic compound. If the ground-state electronic configuration of \ce{X} is $1s^{2}\,2s^{2}\,2p^{3}$, the simplest formula for this compound is:

A mixture of 2.3 g formic acid (\ce{HCOOH}) and 4.5 g oxalic acid (\ce{(COOH)2}) is treated with conc. \ce{H2SO4}. The evolved gaseous mixture is passed through \ce{KOH} pellets. The weight (in g) of the remaining gas is

In which of the following is the number of water molecules maximum?

The bond dissociation energies of $\ce{X2}$, $\ce{Y2}$ and $\ce{XY}$ are in the ratio of $1 : 0.5 : 1$. $\Delta H$ for the formation of $\ce{XY}$ is $-200\ kJ\,mol^{-1}$. The bond dissociation energy of $\ce{X2}$ will be

Identify the major products $P$, $Q$ and $R$ in the following sequence of reactions: \ce{C6H6 + CH3CH2CH2Cl ->[{anhydrous AlCl3}] P} \ce{P ->[{(i) O2}][{(ii) H3O+}] Q + R}

A mixture of 2.3 g formic acid (\ce{HCOOH}) and 4.5 g oxalic acid (\ce{(COOH)2}) is treated with conc. \ce{H2SO4}. The evolved gaseous mixture is passed through \ce{KOH} pellets. The weight (in g) of the remaining gas at STP will be

Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their:

Compound $A$, \ce{C8H10O}, reacts with NaOI (produced by reacting $Y$ with NaOH) and yields a yellow precipitate with characteristic smell. $A$ and $Y$ are respectively:

Identify the major products P, Q and R in the following sequence of reactions: \ce{C6H6 + CH3CH2CH2Cl ->[\text{anhyd. } AlCl3] P} \ce{P ->[(i) O2][(ii) H3O+/\Delta] Q + R}

The compound A on treatment with \ce{Na} gives B, and with \ce{PCl5} gives C. B and C react together to give diethyl ether. A, B and C are, in order,

In the reaction \ce{C6H5OH + CHCl3 + NaOH -> salicylaldehyde} the electrophile involved is

Compound A, \ce{C8H10O}, reacts with \ce{NaOI} (produced by reacting Y with \ce{NaOH}) to yield a yellow precipitate with a characteristic smell. A and Y are respectively

Match the metal ions given in Column I with the spin magnetic moments of the ions given in Column II and assign the correct code: Column I (a) $\ce{Co^3+}$ (b) $\ce{Cr^3+}$ (c) $\ce{Fe^3+}$ (d) $\ce{Ni^2+}$ Column II (i) $\sqrt{8}$ BM (ii) $\sqrt{35}$ BM (iii) $\sqrt{3}$ BM (iv) $\sqrt{24}$ BM (v) $\sqrt{15}$ BM Choose the correct option:

Iron carbonyl, \ce{Fe(CO)5}, is:

The type of isomerism shown by the complex \ce{[CoCl2(en)2]} is:

The geometry and magnetic behaviour of the complex \ce{[Ni(CO)4]} are:

The compound A on treatment with $\ce{Na}$ gives B, and with $\ce{PCl5}$ gives C. B and C react together to give diethyl ether. A, B and C, in order, are:

The compound $\ce{C7H8}$ undergoes the following reactions: $\ce{C7H8 ->[Cl2] A ->[Br2/Fe] B ->[Zn/HCl] C}$ The product C is:

Hydrocarbon A reacts with bromine by substitution to form an alkyl bromide, which by the Wurtz reaction is converted to a gaseous hydrocarbon containing less than four carbon atoms. A is:

Which of the following compounds can form a zwitterion?

The difference between amylose and amylopectin is:

Match the metal ions given in Column I with the spin magnetic moments of the ions given in Column II and assign the correct code: Column I (a) \ce{Co^3+} (b) \ce{Cr^3+} (c) \ce{Fe^3+} (d) \ce{Ni^2+} Column II (i) $\sqrt{8}$ BM (ii) $\sqrt{35}$ BM (iii) $\sqrt{3}$ BM (iv) $\sqrt{24}$ BM (v) $\sqrt{15}$ BM Choose the correct answer:

Which one of the following ions exhibits d-d transition and paramagnetism as well?

Which one of the following statements correctly describes the difference between a first-order and a second-order reaction?

When the initial concentration of the reactant is doubled, the half-life period of a zero order reaction

Consider the change in oxidation state of bromine corresponding to the standard reduction (electrode) potentials shown for each successive step: \ce{BrO4^-} $\xrightarrow{+1.82\ \text{V}}$ \ce{BrO3^-} $\xrightarrow{+1.50\ \text{V}}$ \ce{HBrO} $\xrightarrow{+1.595\ \text{V}}$ \ce{Br2} $\xrightarrow{+1.0652\ \text{V}}$ \ce{Br^-} Then the species undergoing disproportionation is

Nitration of aniline in strong acidic medium also gives $m$-nitroaniline because