Given below are two statements :

Question: Given below are two statements : Statement I : A mixture of chloroform and aniline can be separated by simple distillation. Statement II : When separating aniline from a mixture of aniline and water by steam distillation aniline boils below its boiling point. In the light of the above statements, choose the most appropriate answer from the options given below.Statement-I is false but Statement II is trueBoth Statement-I and Statement II are falseStatement-I is true but Statement II is ...

Read More →

The ionization enthalpy of

Question: The ionization enthalpy of $\mathrm{Na}^{+}$formation from $\mathrm{Na}_{(\mathrm{g})}$ is $495.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$, while the electron gain enthalpy of $\mathrm{Br}$ is $-325.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$. Given the lattice enthalpy of $\mathrm{NaBr}$ is $-728.4 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The energy for the formation of $\mathrm{NaBr}$ ionic solid is $(-)$ ___________$\times 10^{-1} \mathrm{~kJ} \mathrm{~mol}^{-1}$. Solution: $\Delta \mathrm{H}_{\text {forma...

Read More →

Solve this following

Question: Let $f: \mathbf{R} \rightarrow \mathbf{R}$ be defined as $f(x+y)+f(x-y)=2 f(x) f(y), f\left(\frac{1}{2}\right)=-1 .$ Then, the value of $\sum_{k=1}^{20} \frac{1}{\sin (k) \sin (k+f(k))}$ is equal to : $\operatorname{cosec}^{2}(21) \cos (20) \cos (2)$$\sec ^{2}(1) \sec (21) \cos (20)$$\operatorname{cosec}^{2}(1) \operatorname{cosec}(21) \sin (20)$$\sec ^{2}(21) \sin (20) \sin (2)$Correct Option: , 3 Solution: $f(x)=\cos \lambda x$ $\because \mathrm{f}\left(\frac{1}{2}\right)=-1$ So, $-1...

Read More →

Identify the major products A and B respectively

Question: Identify the major products A and B respectively in the following reactions of phenol. Correct Option: , 2 Solution:...

Read More →

Using the provided information

Question: Using the provided information in the following paper chromatogram : the calculate $R_{f}$ value of $A$_________ $\times 10^{-1}$ Solution: $\mathrm{R}_{\mathrm{f}}=\frac{\text { Distance travelled by compound }}{\text { Distance travelled by solvent }}$ on chromatogram distance travelled by cmopound is $\rightarrow 2 \mathrm{~cm}$ Distance travelled by solvent $=5 \mathrm{~cm}$ So $\mathrm{R}_{\mathrm{f}}=\frac{2}{5}=4 \times 10^{-1}=0.4$...

Read More →

The electrode potential

Question: The electrode potential of $\mathrm{M}^{2+} / \mathrm{M}$ of $3 \mathrm{~d}$-series elements shows positive value of:$\mathrm{Zn}$$\mathrm{Fe}$$\mathrm{Co}$$\mathrm{Cu}$Correct Option: , 4 Solution: Only copper shows positive value for electrode potential of $\mathrm{M}^{2+} / \mathrm{M}$ of $3 \mathrm{~d}$-series elements. $\mathrm{E}^{\ominus} / \mathrm{V}_{\left(\mathrm{Cu}^{2+} / \mathrm{Cu}\right)}:+0.34$...

Read More →

Match List -I with List - II

Question: Match List -I with List - II Choose the most appropriate answer from the options given below.(a) $\rightarrow$ (i), (b) $\rightarrow$ (iii), (c) $\rightarrow$ (iv), (d) $\rightarrow$ (ii)(a) $\rightarrow$ (ii), (b) $\rightarrow$ (i), (c) $\rightarrow$ (iv), (d) $\rightarrow$ (iii)(a) $\rightarrow$ (ii), (b) $\rightarrow$ (iv), (c) $\rightarrow$ (i), (d) $\rightarrow$ (iii)(a) $\rightarrow$ (iii), (b) $\rightarrow$ (i), (c) $\rightarrow$ (ii), (d) $\rightarrow$ (iv)Correct Option: , 2 S...

Read More →

The major components in "Gun Metal" are :

Question: The major components in "Gun Metal" are :$\mathrm{Cu}, \mathrm{Zn}$ and $\mathrm{Ni}$$\mathrm{Cu}, \mathrm{Sn}$ and $\mathrm{Zn}$$\mathrm{Al}, \mathrm{Cu}, \mathrm{Mg}$ and $\mathrm{Mn}$$\mathrm{Cu}, \mathrm{Ni}$ and $\mathrm{Fe}$Correct Option: , 2 Solution: The major components in "Gun Metal" are $\mathrm{Cu}: 87 \%$ $\mathrm{Zn}: 3 \%$ Sn : $10 \%$...

Read More →

The orbital having two radial as well as two angular nodes is -

Question: The orbital having two radial as well as two angular nodes is -$3 \mathrm{p}$$4 \mathrm{f}$$4 \mathrm{~d}$$5 \mathrm{~d}$Correct Option: , 4 Solution: $\mathrm{n}-l-1=2$ $1=2$ $n-2-1=2$ $\mathrm{n}=5$...

Read More →

Consider the following chemical reaction.

Question: Consider the following chemical reaction. The number of $\mathrm{sp}^{2}$ hybridized carbon atom(s) present in the product is_________ Solution:...

Read More →

Statements about heavy water are given below.

Question: Statements about heavy water are given below. A. Heavy water is used in exchange reactions for the study of reaction mechanisms. B. Heavy water is prepared by exhaustive electrolysis of water C. Heavy water has higher boiling point than ordinary water. D. Viscosity of $\mathrm{H}_{2} \mathrm{O}$ is greater than $\mathrm{D}_{2} \mathrm{O}$A, B and C only$\mathrm{A}$ and $\mathrm{B}$ only$\mathrm{A}$ and $\mathrm{D}$ only$\mathrm{A}$ and $\mathrm{C}$ onlyCorrect Option: 1 Solution: Heavy...

Read More →

0.4g mixture of

Question: $0.4 \mathrm{~g}$ mixture of $\mathrm{NaOH}, \mathrm{Na}_{2} \mathrm{CO}_{3}$ and some inert impurities was first titrated with $\frac{\mathrm{N}}{10} \mathrm{HCl}$ using phenolphthalein as an indicator, $17.5 \mathrm{~mL}$ of $\mathrm{HCl}$ was required at the end point. After this methyl orange was added and titrated. $1.5 \mathrm{~mL}$ of same $\mathrm{HCl}$ was required for the next end point. The weight percentage of $\mathrm{Na}_{2} \mathrm{CO}_{3}$ in the mixture is___________ ....

Read More →

The gas released during anaerobic degradation of vegetation may lead to :

Question: The gas released during anaerobic degradation of vegetation may lead to :Ozone holeAcid rainCorrosion of metalsGlobal warming and cancerCorrect Option: , 4 Solution: The gas $\mathrm{CH}_{4}$ evolved due to anaerobic degradation of vegetation which causes global warming and cancer....

Read More →

For the reaction,

Question: For the reaction, $a A+b B \rightarrow c C+d D$, the plot of $\log \mathrm{k} \mathrm{vs} \frac{1}{\mathrm{~T}}$ is given below : The temperature at which the rate constant of the reaction is $10^{-4} \mathrm{~s}^{-1}$ is __________$\mathrm{K}$. (Rounded-off to the nearest integer) [Given : The rate constant of the reaction is $10^{-5} \mathrm{~s}^{-1}$ at $500 \mathrm{~K}$.] Solution: $\log \mathrm{K}=\log \mathrm{A}-\frac{\mathrm{Ea}}{2.303 \mathrm{RT}}$ $\mid$ Slope $\mid=\frac{\mat...

Read More →

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

Question: Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R Assertion A : Dipole-dipole interactions are the only non-covalent interactions, resulting in hydrogen bond formation. Reason $\mathbf{R}$ : Fluorine is the most electronegative element and hydrogen bonds in HF are symmetrical. In the light of the above statements, choose the most appropriate answer from the options given below.$\mathrm{A}$ is false but $\mathrm{R}$ is trueBoth $\mathr...

Read More →

Match List I with List II.

Question: Match List I with List II. Choose the correct answer from the options given below :(a) $\rightarrow$ (iv), (b) $\rightarrow$ (iii), (c) $\rightarrow$ (ii), (d) $\rightarrow$ (i)(a) $\rightarrow$ (ii), (b) $\rightarrow$ (i), (c) $\rightarrow$ (iv), (d) $\rightarrow$ (iii)(a) $\rightarrow$ (iii), (b) $\rightarrow$ (iv), (c) $\rightarrow$ (i), (d) $\rightarrow$ (ii)(a) $\rightarrow$ (i), (b) $\rightarrow$ (ii), (c) $\rightarrow$ (iii), (d) $\rightarrow$ (iv)Correct Option: , 3 Solution: (...

Read More →

Match List -I with List - II

Question: Match List -I with List - II Choose the most appropriate answer from the options given below -(a) $\rightarrow$ (ii), (b) $\rightarrow$ (iii), (c) $\rightarrow$ (iv), (d) $\rightarrow$ (i)(a) $\rightarrow$ (i), (b) $\rightarrow$ (iv), (c) $\rightarrow$ (iii),(d) $\rightarrow$ (ii)(a) $\rightarrow$ (i), (b) $\rightarrow$ (iii), (c) $\rightarrow$ (iv),(d) $\rightarrow$ (ii)(a) $\rightarrow$ (iv), (b) $\rightarrow$ (i), (c) $\rightarrow$ (ii), (d) $\rightarrow$ (iii)Correct Option: 1 Solu...

Read More →

Out of the following, which type of interaction is responsible for the stabilisation of a-helix structure of proteins ?

Question: Out of the following, which type of interaction is responsible for the stabilisation of a-helix structure of proteins ?Ionic bondingHydrogen bondingCovalent bondingvander Waals forcesCorrect Option: , 2 Solution: Hydrogen bonding is responsible for the stacking of $\alpha$-helix structure of protein....

Read More →

The reaction of cyanamide,

Question: The reaction of cyanamide, $\mathrm{NH}_{2} \mathrm{CN}_{(s)}$ with oxygen was run in a bomb calorimeter and $\Delta \mathrm{U}$ was found to be $-742.24 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The magnitude of $\Delta \mathrm{H}_{298}$ for the reaction $\mathrm{NH}_{2} \mathrm{CN}_{(\mathrm{s})}+\frac{3}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{N}_{2(\mathrm{~g})}+\mathrm{O}_{2}(\mathrm{~g})+\mathrm{H}_{2} \mathrm{O}_{(l)}$ is_______________$\mathrm{kJ}$. (Rounded off to the neare...

Read More →

The presence of ozone in troposphere

Question: The presence of ozone in troposphere Protects us from the UV radiationProtects us from the X-ray radiationProtects us from greenhouse effectgenerates photochemical smogCorrect Option: , 4 Solution: The presence of ozone in troposphere generates photochemical smog....

Read More →

A car tyre is filled with nitrogen

Question: A car tyre is filled with nitrogen gas at $35 \mathrm{psi}$ at $27^{\circ} \mathrm{C}$. It will burst if pressure exceeds $40 \mathrm{psi}$. The temperature in ${ }^{\circ} \mathrm{C}$ at which the car tyre will burst is _________(Rounded-off to the nearest integer) Solution: $\mathrm{P} \propto \mathrm{T}$ $\frac{\mathrm{P}_{2}}{\mathrm{P}_{1}}=\frac{\mathrm{T}_{2}}{\mathrm{~T}_{1}} \Rightarrow \frac{40}{35}=\frac{\mathrm{T}_{2}}{300}$ $\mathrm{T}_{2}=342.854 \mathrm{~K}$ $=69.70^{\ci...

Read More →

Find A, B and C in the following reactions :

Question: Find $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ in the following reactions : $\mathrm{NH}_{3}+\mathrm{A}+\mathrm{CO}_{2} \rightarrow\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}$ $\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}+\mathrm{H}_{2} \mathrm{O}+\mathrm{B} \rightarrow \mathrm{NH}_{4} \mathrm{HCO}_{3}$ $\mathrm{NH}_{4} \mathrm{HCO}_{3}+\mathrm{NaCl} \rightarrow \mathrm{NH}_{4} \mathrm{Cl}+\mathrm{C}$$\mathrm{A}-\mathrm{O}_{2} ; \mathrm{B}-\mathrm{CO}_{2} ; \mathrm{C}-\mathrm{...

Read More →

Solve this following

Question: For real numbers $\alpha$ and $\beta \neq 0$, if the point of intersection of the straight lines $\frac{x-\alpha}{1}=\frac{y-1}{2}=\frac{z-1}{3}$ and $\frac{x-4}{\beta}=\frac{y-6}{3}=\frac{z-7}{3}$ lies on the plane $x+2 y-z=8$, then $\alpha-\beta$ is equal to: 5937Correct Option: , 4 Solution: First line is $(\phi+\alpha, 2 \phi+1,3 \phi+1)$ and second line is $(\mathrm{q} \beta+4,3 \mathrm{q}+6,3 \mathrm{q}+7)$. For intersection $\phi+\alpha=\mathrm{q} \beta+4$ ............(I) $2 \ph...

Read More →

Given below are two statements :

Question: Given below are two statements : Statement I : Colourless cupric metaborate is reduced to cuprous metaborate in a luminous flame. Statement II : Cuprous metaborate is obtained by heating boric anhydride and copper sulphate in a non-luminous flame. In the light of the above statements, choose the most appropriate answer from the options given below.Statement I is true but Statement II is falseBoth Statement I and Statement II are falseStatement I is false but Statement II is trueBoth St...

Read More →

In basic medium

Question: In basic medium $\mathrm{CrO}_{4}^{2-}$ oxidises $\mathrm{S}_{2} \mathrm{O}_{3}^{2-}$ to form $\mathrm{SO}_{4}{ }^{2-}$ and itself changes into $\mathrm{Cr}(\mathrm{OH})_{4}^{-}$. The volume of $0.154 \mathrm{M} \mathrm{CrO}_{4}^{2-}$ required to react with $40 \mathrm{~mL}$ of $0.25 \mathrm{M} \mathrm{S}_{2} \mathrm{O}_{3}^{2-}$ is_____________ $\mathrm{mL}$. (Rounded-off to the nearest integer) Solution: $\stackrel{+6}{\mathrm{CrO}_{4}^{2-}}+\stackrel{+2}{\mathrm{~S}}_{2} \mathrm{O}_...

Read More →