In presence of \( \mathrm{HCl}, \mathrm{H}_{2} \mathrm{~S} \) results the precipitation of Group-2 elements but not Gp-4
elements during qualitative analysis. It is due to

During the fusion of organic compound with sodium metal, nitrogen present in the organic
compound is converted into

\( \left[\mathrm{Fe}\left(\mathrm{NO}_{2}\right)_{3} \mathrm{Cl}_{3}\right] \) and \( \left[\mathrm{Fe}(\mathrm{O}-\mathrm{NO})_{} \mathrm{Cl}_{3}\right] \) shows

Match List-I with List-II
\begin{array}{|l|l|l|l|}\hline & \text{List-I (Types of redox reactions)} & & \text{List-II (Examples)} \\\hline \text{a}. & \text{Combination reaction} & \text{(i)} & \mathrm{Cl}_{2(\mathrm{~g})}+2 \mathrm{Br}_{(\mathrm{aq})}^{-} \rightarrow 2 \mathrm{Cl}_{(\mathrm{aq})}^{-}+\mathrm{Br}_{2(\mathrm{l})} \\\hline \text{b.} & \text{Decomposition reaction} & \text{(ii)} & 2 \mathrm{H}_2 \mathrm{O}_{2(\mathrm{aq})} \rightarrow 2 \mathrm{H}_2 \mathrm{O}_{(1)}+\mathrm{O}_{2(\mathrm{~g})} \\\hline \text{c.} & \text{Displacement reaction} & \text{(iii)} & \mathrm{CH}_{4(\mathrm{~g})}+2 \mathrm{O}_{2(\mathrm{~g})} \xrightarrow{\Delta} \mathrm{CO}_{2(\mathrm{~g})}+2 \mathrm{H}_2 \mathrm{O}_{(1)} \\\hline \text{d.} & \text{Disproportionation reaction} & \text{(iv)} & \mathrm{H}_2 \mathrm{O}_{(1)} \xrightarrow{\Delta} 2 \mathrm{H}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})} \\\hline\end{array}

Choose the correct answer from the options given below.

Methoxy methane and ethanol are

In the electrolysis of acidulated water, it is desired to obtain \(1.12\) cc of hydrogen per second under STP condition. The current to be passed is

The \(\mathrm{C}-\mathrm{H}\) bond and \(\mathrm{C}-\mathrm{C}\) bond in ethane are formed by which of the following types of overlap?

Which one of the following sets of quantum numbers represents the highest energy level in an atom?

If an electron is revolving in its Bohr orbit having Bohr radius of \(0.529 Å\), then the radius of third orbit is

When \(0.0106\) mole of acetic acid was dissolved in \(1\) kg of water, the freezing point depression for this strength of acid was \(0.0205\) K. If the calculated freezing point depression is \(0.0197\) K, Van't Hoff factor (i) and degree of dissociation of acetic acid respectively are

\(\lim _{x \rightarrow 0} \frac{\log _{e}(1+x)}{3^{x}-1}\) is equal to

The points \((11,9),(2,1)\) and \((2,-1)\) are the mid-points of the sides of the triangle. Then, the centroid is

Two capacitors of \( 3 \mu \mathrm{F} \) and \( 6 \mu \mathrm{F} \) are connected in series and a potential difference of \( 900 \mathrm{~V} \) is applied across the combination. They are then disconnected and reconnected in parallel. The potential difference across the combination is