The number of unpaired electrons in Ni (atomic number \(=28\) ) are

Addition of excess potassium iodide solution to a solution of mereuric chloride gives the halide complex

Equal weights of \(\mathrm{CH}_{4}\) and \(\mathrm{H}_{2}\) are mixed in an empty container at \(25^{\circ} \mathrm{C}\). the fraction of the total pressure exerted by \(\mathrm{H}_{2}\) is

1,4 -dimethylbenzene on heating with anhydrous \(\mathrm{AlCl}_{3}\) and HCl produces

In aluminium extraction by the Bayer process, alumina is extracted from bauxite by sodium hydroxide at high temperature and pressures :
\(\mathrm{Al}_2 \mathrm{O}_3(\mathrm{~s})+2 \mathrm{OH}^{-}(\mathrm{aq}) \rightarrow 2 \mathrm{Al}_2 \mathrm{O}_2(\mathrm{aq})+\mathrm{H}_2 \mathrm{O}(1)\)

Solid impurities such as \(\mathrm{Fe}_2 \mathrm{O}_3\) and \(\mathrm{SiO}_2\) are removed and then \(\mathrm{Al}(\mathrm{OH})_4^{-}\)is reprecipitated : \(2 \mathrm{Al}(\mathrm{OH})_4^{-} \rightarrow \mathrm{Al}_2 \mathrm{O}_3 \cdot 3 \mathrm{H}_2 \mathrm{O}(\mathrm{s})+2 \mathrm{OH}^{-}\)(aq) . In the industrial world :

Which of the following has the strongest H-bond?

Equal masses of ethane and hydrogen are mixed in a empty container at \(298 \mathrm{~K}\). The fraction of total pressure exerted by hydrogen is

The value of \(\int_{-2}^2(x \cos x+\sin x+1) d x\) is

What are the charges stored in the \(1 \mu \mathrm{~F}\) and \(2 \mu \mathrm{~F}\) capacitors in the circuit as shown in figure once the current (I) become steady?

A neutral conducting solid sphere of radius \(\mathrm{R}\) has two spherical cavities of radius a and \(b\) as shown in the figure. Centre to centre distance between two cavities is \(c . q_a\) and \(q_b\) charges are placed at the centres of cavities respectively. The force between \(q_a\) and \(q_b\) is

If \(U_n(n=1,2)\) denote the \(n^{\text {th }}\) derivative \((n=1,2)\) of \(U(x)=\frac{L x+M}{x^2-2 B x+C}(L, M, B, C\) are constants \()\), then \(P U_2+Q U_1\) \(+R U=0\), holds for

A rectangle \(A B C D\) has its side parallel to the line \(y=2 x\) and vertices \(A, B, D\) are on lines \(y=1, x=1\) and \(x=-1\) respectively. The coordinate of \(C\) can be

Three blocks are pushed with a force \(\mathrm{F}\) across a frictionless table as shown in figure. Let \(\mathrm{N}_{1}\) be the contact force between the left two blocks and \(\mathrm{N}_{2}\) be the contact force between the right two blocks. Then