Photoelectric emission is observed from a metal surface with incident frequencies${\nu }_{1}and{\nu }_2$ where ${\nu }_1>{\nu }_2$. If the kinetic energies of the photoelectrons emitted in the two cases are in the ratio $2:1$, then the threshold frequency ${\nu }_o$ of the metal is

When the sample of copper with zinc impurity is to be purified by

electrolysis, the appropriate electrodes of cathode and anode are

[AIEEE 2002]

A compound shows a large dipole moment. Which structure should be used to adequately explain the observation?

A sample of $0.318\text{g}$ of pure sodium carbonate is titrated with $HCl$ solution. A volume of $60\text{mL}$ is required to reach the end point. Calculate the molarity of the acid.

The equivalent conductance of NaCl at concentration C and at infinite dilution are ${\lambda }_C$ and ${\lambda }_{\infty }$ respectively. The correct relationship between ${\lambda }_{C}and{\lambda }_{\infty }$ is given as (where, the constant B is positive)

In hte following reaction
$2S{O}_2\left(g\right)+O_2\left(g\right)\rightleftharpoons 2S{O}_3\left(g\right)$
the equilibrium is not attained. The rate of forward reaction is greater than that of backward reaction. Thus, which of the following is the correct relation between $K_p$ and $Q_p$?

A redox reaction among the following is

The oxidation state of $N$ in $N{H}_{4}N{O}_3$ is

The number of $C{l}^{-}$ ions present in 0.1 mol of $CaC{l}_2$ is:

Consider a solution having $\left[H^{+}\right]={10}^{-5}M$ at ${25}^{\circ }C$, then $O{H}^{-}$ ion concentration of this solution at the given temperature is :

Which aerosols deplete ozone?

How many ions are produced from the complex, $\left[Co\right(N{H}_3{)}_{6}C{l}_2]$ in solution?

$x{H}_{2}S{O}_4+yS{O}_2+zN{a}_{2}Cr{O}_4⟶C{r}_2(S{O}_4{)}_3+aN{a}_{2}S{O}_4+b{H}_{2}O$



In the above reaction, x, y, z, a and b are?

Which of the following isomer(s) represent a 'D' configuration?

Calculate the number of moles in 1 × 10²³ molecules of CO₂

When sodium acetate is added to aqueous solution of acetic acid, then why does the ph value increase?​

Consider the following cases A and B in Ostwald-Walker Method:

Case A : Dry air is passed through a pure solvent and then, a dehydrating agent.



Case B: Dry air is passed through a pure solvent and then a solution with non-volatile solute and then, a dehydrating agent



Here,

$p^{\circ }\text{is the vapour pressure of the pure solvent}$

$p_s\text{is the vapour pressure of the solution}$



Choose the incorrect option:

Aldol condensation between the following compounds followed by
dehydration gives methyl vinyl ketone:

Cyclohexene on ozonolysis followed by reaction with zinc dust and water gives compound E. Compound E on further treatment with aqueous KOH yields compound F. Compound F is