The products A and B formed in the following reaction scheme are respectively

The correct stability order of carbocations is

Which among the following purification methods is based on the principle of "Solubility" in two different solvents?

IUPAC name of following compound is :

The solution from the following with highest depression in freezing point/lowest freezing point is

Given below are two statements:

Statement - I: Since Fluorine is more electronegative than nitrogen, the net dipole moment of $$\mathrm{NF}_3$$ is greater than $$\mathrm{NH}_3$$.

Statement - II: In $$\mathrm{NH}_3$$, the orbital dipole due to lone pair and the dipole moment of $$\mathrm{NH}$$ bonds are in opposite direction, but in $$\mathrm{NF}_3$$ the orbital dipole due to lone pair and dipole moments of N-F bonds are in same direction.

In the light of the above statements, choose the most appropriate from the options given below:

A and B formed in the following reactions are:

$$\begin{aligned} & \mathrm{CrO}_2 \mathrm{Cl}_2+4 \mathrm{NaOH} \rightarrow \mathrm{A}+2 \mathrm{NaCl}+2 \mathrm{H}_2 \mathrm{O}, \\ & \mathrm{A}+2 \mathrm{HCl}+2 \mathrm{H}_2 \mathrm{O}_2 \rightarrow \mathrm{B}+3 \mathrm{H}_2 \mathrm{O} \end{aligned}$$

If a substance '$$A$$' dissolves in solution of a mixture of '$$B$$' and '$$C$$' with their respective number of moles as $$\mathrm{n}_{\mathrm{A}}, \mathrm{n}_{\mathrm{B}}$$ and $$\mathrm{n}_{\mathrm{C}_3}$$. Mole fraction of $$\mathrm{C}$$ in the solution is

The molecule / ion with square pyramidal shape is

Given below are two statements:

Statement - I: High concentration of strong nucleophilic reagent with secondary alkyl halides which do not have bulky substituents will follow $$\mathrm{S}_{\mathrm{N}}{ }^2$$ mechanism.

Statement - II: A secondary alkyl halide when treated with a large excess of ethanol follows $$\mathrm{S}_{\mathrm{N}}{ }^1$$ mechanism.

In the light of the above statements, choose the most appropriate from the options given below:

Choose the correct statements about the hydrides of group 15 elements.

A. The stability of the hydrides decreases in the order $$\mathrm{NH}_3>\mathrm{PH}_3>\mathrm{AsH}_3> \mathrm{SbH}_3>\mathrm{BiH}_3$$.

B. The reducing ability of the hydride increases in the order $$\mathrm{NH}_3<\mathrm{PH}_3<\mathrm{AsH}_3 <\mathrm{SbH}_3<\mathrm{BiH}_3$$.

C. Among the hydrides, $$\mathrm{NH}_3$$ is strong reducing agent while $$\mathrm{BiH}_3$$ is mild reducing agent.

D. The basicity of the hydrides increases in the order $$\mathrm{NH}_3<\mathrm{PH}_3<\mathrm{AsH}_3< \mathrm{SbH}_3<\mathrm{BiH}_3$$.

Choose the most appropriate from the options given below :

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R:

Assertion A: $$\mathrm{H}_2 \mathrm{Te}$$ is more acidic than $$\mathrm{H}_2 \mathrm{~S}$$.

Reason R: Bond dissociation enthalpy of $$\mathrm{H}_2 \mathrm{Te}$$ is lower than $$\mathrm{H}_2 \mathrm{~S}$$.

In the light of the above statements, choose the most appropriate from the options given below:

Alkaline oxidative fusion of $$\mathrm{MnO}_2$$ gives "A" which on electrolytic oxidation in alkaline solution produces B. A and B respectively are

Salicylaldehyde is synthesized from phenol, when reacted with

m-chlorobenzaldehyde on treatment with 50% KOH solution yields :

Products A and B formed in the following set of reactions are

The orange colour of $$\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$$ and purple colour of $$\mathrm{KMnO}_4$$ is due to

The coordination geometry around the manganese in decacarbonyldimanganese $$(0)$$ is

Reduction potential of ions are given below:

$$\begin{array}{ccc} \mathrm{ClO}_4^{-} & \mathrm{IO}_4^{-} & \mathrm{BrO}_4^{-} \\ \mathrm{E}^{\circ}=1.19 \mathrm{~V} & \mathrm{E}^{\circ}=1.65 \mathrm{~V} & \mathrm{E}^{\circ}=1.74 \mathrm{~V} \end{array}$$

The correct order of their oxidising power is :

Given below are two statements:

Statement - I: Along the period, the chemical reactivity of the elements gradually increases from group 1 to group 18 .

Statement - II: The nature of oxides formed by group 1 elements is basic while that of group 17 elements is acidic.

In the light of the above statements, choose the most appropriate from the options given below:

The total number of correct statements, regarding the nucleic acids is _________.

A. RNA is regarded as the reserve of genetic information

B. DNA molecule self-duplicates during cell division

C. DNA synthesizes proteins in the cell

D. The message for the synthesis of particular proteins is present in DNA

E. Identical DNA strands are transferred to daughter cells.

Number of metal ions characterized by flame test among the following is ________.

$$\mathrm{Sr}^{2+}, \mathrm{Ba}^{2+}, \mathrm{Ca}^{2+}, \mathrm{Cu}^{2+}, \mathrm{Zn}^{2+}, \mathrm{Co}^{2+}, \mathrm{Fe}^{2+}$$

Number of spectral lines obtained in $$\mathrm{He}^{+}$$ spectra, when an electron makes transition from fifth excited state to first excited state will be

Total number of species from the following which can undergo disproportionation reaction is ________.

$$\mathrm{H}_2 \mathrm{O}_2, \mathrm{ClO}_3^{-}, \mathrm{P}_4, \mathrm{Cl}_2, \mathrm{Ag}, \mathrm{Cu}^{+1}, \mathrm{~F}_2, \mathrm{NO}_2, \mathrm{K}^{+}$$

Number of geometrical isomers possible for the given structure is/are _________.

The $$\mathrm{pH}$$ of an aqueous solution containing $$1 \mathrm{M}$$ benzoic acid $$\left(\mathrm{pK}_{\mathrm{a}}=4.20\right)$$ and $$1 \mathrm{M}$$ sodium benzoate is 4.5. The volume of benzoic acid solution in $$300 \mathrm{~mL}$$ of this buffer solution is _________ $$\mathrm{mL}$$. (given : $$\log 2=0.3$$)

$$\mathrm{NO}_2$$ required for a reaction is produced by decomposition of $$\mathrm{N}_2 \mathrm{O}_5$$ in $$\mathrm{CCl}_4$$ as by equation

$$2 \mathrm{~N}_2 \mathrm{O}_{5(\mathrm{~g})} \rightarrow 4 \mathrm{NO}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})}$$

The initial concentration of $$\mathrm{N}_2 \mathrm{O}_5$$ is $$3 \mathrm{~mol} \mathrm{~L}^{-1}$$ and it is $$2.75 \mathrm{~mol} \mathrm{~L}^{-1}$$ after 30 minutes.

The rate of formation of $$\mathrm{NO}_2$$ is $$\mathrm{x} \times 10^{-3} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~min}^{-1}$$, value of $$\mathrm{x}$$ is _________. (nearest integer)

Number of complexes which show optical isomerism among the following is ________.

$$\text { cis- }\left[\mathrm{Cr}(\mathrm{ox})_2 \mathrm{Cl}_2\right]^{3-},\left[\mathrm{Co}(\text {en})_3\right]^{3+}, \text { cis- }\left[\mathrm{Pt}(\text {en})_2 \mathrm{Cl}_2\right]^{2+}, \text { cis- }\left[\mathrm{Co}(\text {en})_2 \mathrm{Cl}_2\right]^{+}, \text {trans- }\left[\mathrm{Pt}(\text {en})_2 \mathrm{Cl}_2\right]^{2+}, \text { trans- }\left[\mathrm{Cr}(\mathrm{ox})_2 \mathrm{Cl}_2\right]^{3-}$$

2-chlorobutane $$+\mathrm{Cl}_2 \rightarrow \mathrm{C}_4 \mathrm{H}_8 \mathrm{Cl}_2$$ (isomers)

Total number of optically active isomers shown by $$\mathrm{C}_4 \mathrm{H}_8 \mathrm{Cl}_2$$, obtained in the above reaction is _________.

Two reactions are given below:

$$\begin{aligned} & 2 \mathrm{Fe}_{(\mathrm{s})}+\frac{3}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{Fe}_2 \mathrm{O}_{3(\mathrm{~s})}, \Delta \mathrm{H}^{\circ}=-822 \mathrm{~kJ} / \mathrm{mol} \\ & \mathrm{C}_{(\mathrm{s})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{(\mathrm{g})}, \Delta \mathrm{H}^{\circ}=-110 \mathrm{~kJ} / \mathrm{mol} \end{aligned}$$

Then enthalpy change for following reaction $$3 \mathrm{C}_{(\mathrm{s})}+\mathrm{Fe}_2 \mathrm{O}_{3(\mathrm{~s})} \rightarrow 2 \mathrm{Fe}_{(\mathrm{s})}+3 \mathrm{CO}_{(\mathrm{g})}$$ is _______ $$\mathrm{kJ} / \mathrm{mol}$$.