The colour of \(\mathrm{Mg}(\mathrm{OH})_2\) precipitate formed when it is precipitated in the presence of magneson reagent is

209 g of an element reacts with chlorine to form 315.5 g of its chloride. What is the weight (in g ) of oxygen that reacts with 418 g of same element?
\((\mathrm{C} \ell=35.5 \mathrm{u} ; \mathrm{O}=16 \mathrm{u})\)

Which of the following sequence of reagents convert propene to 1-chloropropane?

Which one of the following statements is not correct?

Consider the following:
Assertion (A) : Dipole moment of \(\mathrm{NF}_3\) is lesser than \(\mathrm{NH}_3\)
Reason (R) : In NF \({ }_3\), the orbital dipole due to lone pair of electrons is in the opposite direction to the resultant dipole moment of the three N-F bonds
The correct answer is

The standard reduction potentials of \(\mathrm{Zn}^{2+}\left|\mathrm{Zn}, \mathrm{Cu}^{2+}\right| \mathrm{Cu}\) and \(\mathrm{Ag}^{+} \mid \mathrm{Cu}\) and \(\mathrm{Ag}^{+} \mid \mathrm{Ag}\) are respectively \(-0.76,0.34\) and \(0.8 \mathrm{~V}\). The following cells were constructed :
(1) \(\mathrm{Zn}\left|\mathrm{Zn}^{2+}\right|\left|\mathrm{Cu}^{2+}\right| \mathrm{Cu}\)
(2) \(\mathrm{Zn}\left|\mathrm{Zn}^{2+}\right|\left|\mathrm{Ag}^{+}\right| \mathrm{Ag}\)
(3) \(\mathrm{Cu}\left|\mathrm{Cu}^{2+} \| \mathrm{Ag}^{+}\right| \mathrm{Ag}\)
What is the correct order of \(E_{\text {cell }}^{\circ}\) of these cells?

The \(\mathrm{p} K_a\) of a weak acid, benzoic acid and \(\mathrm{p} K_b\) of a weak base, ammonium hydroxide are 4.25 and 4.75 respectively. Then the \(\mathrm{pH}\) of \(0.1 \mathrm{M}\) solution of ammonium benzoate will be

The electric field for an electromangetic wave in free space is \(\mathbf{E}=\mathbf{i} 30 \cos \left(k z-5 \times 10^8 t\right)\), where magnitude of \(E\) is in \(\mathrm{V} / \mathrm{m}\). The magnitude of wave vector, \(k\) is (velocity of em wave in free space \(=3 \times 10^8 \mathrm{~m} / \mathrm{s}\) )

The area (in sq. units) of triangle formed by the tangent and normal at a point $\left(\frac{a}{\sqrt{2}},\frac{b}{\sqrt{2}}\right)$ to the curve $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$ and $X$ -axis is

If the vertices of $\Delta \mathrm{ABC}$ are $A=(2,3,5), B=(-1,3,2), C=(3,5,-2),$ then the area of the $\Delta \mathrm{ABC}$ (in sq. units) is

A solenoid of one meter length and 3.55 cm inner diameter carries a current of 5 A. If the solenoid consists of five closely packed layers each with 700 turns along its length, then the magnetic field at its centre is

Bond energy of \(\mathrm{Cl}_2, \mathrm{Br}_2\) and \(\mathrm{I}_2\) follow the order

The quadratic equation whose roots are \(l\) and \(m\), where
\[
\begin{aligned}
& l=\lim _{\theta \rightarrow 0}\left(\frac{3 \sin \theta-4 \sin ^2 \theta}{\theta}\right), \\
& m=\lim _{\theta \rightarrow 0} \frac{2 \tan \theta}{\theta\left(1-\tan ^2 \theta\right)}, \text { is }
\end{aligned}
\]