List of top Chemistry Questions

At a given temperature, $0.45\,\text{g}$ of acetic acid in $50\,\text{mL}$ of water is shaken with $1.0\,\text{g}$ of charcoal and the pH of the resulting solution is $3.0$. Assume, the adsorption of acetic acid from the aqueous solution by charcoal follows Freundlich isotherm,

\[ \frac{x}{m} = kC^{1/n} \]
If the plot of $\log_{10}(x/m)$ against $\log_{10} C$ gives a straight line with slope $1$, the value of $k$ in $\text{L mol}^{-1}$ is _______.

Given: The molar mass of acetic acid is $60\,\text{g mol}^{-1}$.
The acid dissociation constant of acetic acid is $1.0 \times 10^{-5}$ at the given temperature.
$x$ is the mass (in grams) of acetic acid adsorbed.
$m$ is the mass (in grams) of charcoal.
$C$ is the equilibrium concentration of acetic acid in the solution after the adsorption is complete.
$k$ and $n$ are constants for acetic acid–charcoal system at the given temperature.

X$^{a+}$ and Y$^{b+}$ are hydrogen-like species. The wavelength of light absorbed during the transition between the states with principal quantum numbers $n = 1$ and $n = 2$ of X$^{a+}$ is $\lambda$. The wavelength of light absorbed during the transition between the states with principal quantum numbers $n = 2$ and $n = 4$ of Y$^{b+}$ is $9\lambda$. The lowest possible value of $(a+b)$ is _______.

The correct statement(s) regarding sugars is(are):

Given: Specific rotations of L-(-)-glucose and L-(+)-fructose are $-52.5^\circ$ and $+92.5^\circ$, respectively.

In the following reaction sequence, P, Q, S and T are the major products.

The correct statement(s) about P, Q, S and T is(are)

The correct statement(s) regarding the periodic properties of elements is(are)

Correct statement(s) about the compounds P, Q and R is(are)
$ \text{Xe(g)} + \text{F}_2\text{(g)} \xrightarrow{\text{873 K, 7 bar}}{\text{P}} $
(1 : 5 ratio)
$ \text{P} + \text{O}_2\text{F}_2 \xrightarrow{\text{143 K}}{\text{Q}} + \text{O}_2 $
$ \text{Q} + \text{H}_2\text{O} \xrightarrow{\text{complete hydrolysis}}{\text{R}} + \text{HF} $

For a first-order reaction R $\rightarrow$ P at a given temperature, $k$ is the rate constant. For this reaction, at the given temperature, the concentrations of R and P at a time $t$ are [R] and [P], respectively. The correct graphical representation(s) for this reaction is(are)

A known artificial sweetener X is composed of 4-chloro-4-deoxy-$\alpha$-D-galactose and 1,6-dichloro-1,6-dideoxy-$\beta$-D-fructose joined by a glycosidic linkage.

Structure of D-galactose is given below:

Natural rubber on complete ozonolysis (O$_3$/Zn-H$_2$O) gives compound X as the major product. X gives positive iodoform and Tollen's tests. X on heating with aqueous NaOH gives Y as the major product. Y is

At 300 K, the molar conductivities of the aqueous solutions of three salts at two different concentrations are given below:

The conductivity of a saturated aqueous solution of AgCl is $1.40 \times 10^{-6}$ S cm$^{-1}$ at 300 K. If the solubility of AgCl in water at 300 K is X mol L$^{-1}$, then log$_{10}$(X$^{-1}$) is
(Assume that AgCl dissolved in water ionizes completely and that the molar conductivity of saturated AgCl solution is equal to its limiting molar conductivity.)}

Match the major products obtained in the reactions given in List-I with the corresponding structures in List-II and choose the correct option.

The List-I contains products obtained from the reaction of compounds in List-I with $\mathrm{O_3/Zn-H_2O}$ followed by cyclization (via more stable enolate) in the presence of aqueous $\mathrm{NaOH}$. Match each entry in List-I with appropriate entry in List-II and choose the correct option.

Consider the following species: \[ \mathrm{SOCl_2,\ XeOF_4,\ ClF_3,\ ClF_5,\ XeF_4^+,\ SO_3^{2-},\ XeF_4^+,\ SF_4} \] List-I contains different molecular shapes and List-II contains total number of species with the same molecular shapes from the given species. Match each entry in List-I and choose the correct option.

List-I contains various physical/chemical processes, and List-II contains combinations of changes in enthalpy $(\Delta H)$ and entropy $(\Delta S)$. Match each entry in List-I to the appropriate entry in List-II and choose the correct option.

Treatment of buta-$1,3$-diyne with $\mathrm{NaNH_2}$ (2 equivalents), followed by reaction with excess of trans-$\mathrm{CH_3-CH=CH-CH_2-Br}$ gives $X$ as the major product. The maximum number of carbon atoms that are collinear (in a straight line) in $X$ is ____.

The sum of total number of carbonyl groups $(> \mathrm{C=O})$ present in the major products $X$ and $Y$ in the following reactions is ____.

The total number of all possible isomers for the square planar complex with formula \[ \mathrm{K[M(NCS)(NO_2)(gly)]} \] is _____.

\[ \mathrm{(M = metal\ ion\ and\ gly = NH_2CH_2COO^-)} \]

In the following reaction sequence, $Q$, $R$, $S$ and $T$ are the major products. The correct statement(s) about $Q$, $R$, $S$ and $T$ is(are)

Reaction of $\mathrm{PtF_6}$ with oxygen $(\mathrm{O_2})$ gas results in the formation of an ionic compound, $X^+Y^-$. Correct statement(s) is(are)

Correct statement(s) about the compounds $X$, $Y$ and $Z$ is(are)

The $2s$ and the $2p$ orbital energies of hydrogen atom are $E_{2s}(\mathrm{H})$ and $E_{2p}(\mathrm{H})$, respectively. The $2s$ and the $2p$ orbital energies of lithium atom are $E_{2s}(\mathrm{Li})$ and $E_{2p}(\mathrm{Li})$, respectively. The correct option(s) about the orbital energies is(are)

Considering LiBH$_4$ reduces an ester group to the corresponding alcohol and does not reduce a carboxylic acid group, the correct statement about the major products $P$, $Q$, $R$ and $S$ is

The correct order of dipole moments for the given species is

Consider the following statements: Statement I: Silica in its normal form is almost non-reactive because of very high Si-O bond enthalpy. Statement - II: Silica has no reaction with HF. The correct answer is:

Identify the sets which contain greenhouse gases only: I. $CO_{2}$, $SO_{3}$, $N_{2}$ II. $CO_{2}$, $CH_{4}$, $O_{3}$ III. $O_{2}$, $NO_{2}$, $SO_{2}$ IV. $O_{3}$, CFCs, $N_{2}O$ The correct answer is: