The flame colours of metal ions are due to

\(\mathrm{S}_8\) on heating at a temperature above \(1000 \mathrm{~K}\), changes to \(\mathrm{S}_2\). When 1 mole of \(\mathrm{S}_8\) is heated above \(1000 \mathrm{~K}\), the pressure falls by \(32 \%\) at equilibrium. The equilibrium constant for the conversion is:

Molar conductance of a complex of cobalt is zero. Then its structure would be

The boiling point of a \(4 \%\) aqueous solution of a non-volatile solute \(\mathrm{P}\) is equal to the boiling point of \(\mathrm{X} \%\) solution of another non-volatile solute \(\mathrm{Q}\).
The relation between their Molar masses is \(\mathrm{M}_{\mathrm{Q}}=4 \mathrm{~Mp}\). What is \(\mathrm{X}\) ?

The chemical formula of Hinsberg's reagent is

Lassaigne's test for the detection of nitrogen fails in

The rate constant for a zero order reaction \(\mathrm{A} \rightarrow \mathrm{B}+\mathrm{C}\) is \(6.0 \times 10^{-3} \mathrm{molL}^{-1} \mathrm{~s}^{-1}\).
What would be the time taken for the initial concentration of A to decrease from 0.2 M to 0.024 M ?

Identify the INCORRECT statement

\(\lim _{x \rightarrow 1} \frac{\tan \left(x^{2}-1\right)}{x-1}\) is equal to

The solution of \(\tan ^{-1} x+2 \cot ^{-1} x=\frac{2 \pi}{3}\) is

Which of the following reaction can be used for the preparation of flouromethane?

Transformer works on \(220 \mathrm{~V}\) and its efficiency is \(80 \%\). If output power is \(8 \mathrm{~kW}\), primary current is approximately

Choose the correct metal/ ion from the brackets which ..........
A. has chemical reactivity similar to that of the first few members of the Lanthanoids \((\mathrm{Zn}, \mathrm{Ca}, \mathrm{Fe}, \mathrm{Cu})\).
B. has stable \(4 \mathrm{f}^7\) electronic configuration, but acts as a strong reducing agent and converts to \(\mathrm{M}^{3+}\) state. \(\left(\mathrm{Eu}^{2+}, \mathrm{Ce}^{2+}, \mathrm{Pr}^{2+}, \mathrm{Dy}^{2+}\right)\)
C. is a colorless ion \(\left(\mathrm{Tm}^{3+}, \mathrm{Lu}^{3+}, \mathrm{Gd}^{3+}, \mathrm{Sm}^{3+}\right)\).
D. shows stable +2 oxidation state and is diamagnetic \((\mathrm{Ce}, \mathrm{Sm}, \mathrm{Ho}, \mathrm{Yb})\)