The correct order of spin only magnetic moments for the following complex ions is

Given below are two statements, one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$. Assertion A: The spin only magnetic moment value for $${\left[\mathrm{Fe}(\mathrm{CN}{)}_6\right]}^{3-}$$ is $$1.74\mathrm{BM}$$, whereas for $${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}$$ is $$5.92\mathrm{BM}$$. Reason $$\mathbf{R}$$ : In both complexes, $$\mathrm{Fe}$$ is present in +3 oxidation state. In the light of the above statements, choose the correct answer from the options given below:

The IUPAC name of $${\mathrm{K}}_3\left[\mathrm{Co}{\left({\mathrm{C}}_2{\mathrm{O}}_4\right)}_3\right]$$ is:-

The incorrect statement for the use of indicators in acid-base titration is :

When the hydrogen ion concentration [H$${}^{+}$$] changes by a factor of 1000, the value of pH of the solution __________

Which of the following statement(s) is/are correct? (A) The $\mathrm{pH}$ of $1\times 10^{-8}\mathrm{M}\mathrm{HCl}$ solution is 8 . (B) The conjugate base of ${\mathrm{H}}_2{\mathrm{PO}}_4^{-}$ is ${\mathrm{HPO}}_4^{2-}$. (C) ${\mathrm{K}}_{\mathrm{w}}$ increases with increase in temperature. (D) When a solution of a weak monoprotic acid is titrated against a strong base at half neutralisation point, $\mathrm{pH}=\frac{1}{2}{\mathrm{pK}}_{\mathrm{a}}$ Choose the correct answer from the options given below:

$$25\mathrm{mL}$$ of silver nitrate solution (1M) is added dropwise to $$25\mathrm{mL}$$ of potassium iodide $$(1.05\mathrm{M})$$ solution. The ion(s) present in very small quantity in the solution is/are :

Which one of the following sets of ions represents a collection of isoelectronic species? (Given : Atomic Number : $$\mathrm{F}:9,\mathrm{Cl}:17,\mathrm{Na}=11,\mathrm{Mg}=12,\mathrm{Al}=13,\mathrm{K}=19,\mathrm{Ca}=20,\mathrm{Sc}=21$$)

Arrange the following orbitals in decreasing order of energy. A. $\mathrm{n}=3,\mathrm{l}=0,\mathrm{m}=0$ B. $\mathrm{n}=4,\mathrm{l}=0,\mathrm{m}=0$ C. $\mathrm{n}=3,\mathrm{l}=1,\mathrm{m}=0$ D. $\mathrm{n}=3,\mathrm{l}=2,\mathrm{m}=1$ The correct option for the order is :

Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from $$\mathrm{n}=4$$ to $$\mathrm{n}=2$$ of $${\mathrm{He}}^{+}$$ spectrum

Maximum number of electrons that can be accommodated in shell with $n=4$ are:

The wave function $(\Psi )$ of $2\mathrm{s}$ is given by $${\Psi }_{2\mathrm{s}}=\frac{1}{2\sqrt{2\pi }}{\left(\frac{1}{a_0}\right)}^{1/2}\left(2-\frac{r}{a_0}\right)e^{-r/2a_0}$$ At $r=r_0$, radial node is formed. Thus, $r_0$ in terms of $a_0$

The shortest wavelength of hydrogen atom in Lyman series is $$\lambda$$. The longest wavelength is Balmer series of He$${}^{+}$$ is

The radius of the $$2^{\mathrm{nd}}$$ orbit of $$\mathrm{L}{\mathrm{i}}^{2+}$$ is $$x$$. The expected radius of the $$3^{\mathrm{rd}}$$ orbit of $$\mathrm{B}{\mathrm{e}}^{3+}$$ is

The number of s-electrons present in an ion with 55 protons in its unipositive state is

The magnetic moment of a transition metal compound has been calculated to be 3.87 B.M. The metal ion is

It is observed that characteristic X-ray spectra of elements show regularity. When frequency to the power "n" i.e. $$v^n$$ of X-rays emitted is plotted against atomic number "Z", following graph is obtained. The value of 'n' is :

Given below are two statements: Statement I : According to Bohr's model of hydrogen atom, the angular momentum of an electron in a given stationary state is quantised. Statement II : The concept of electron in Bohr's orbit, violates the Heisenberg uncertainty principle. In the light of the above statements, choose the most appropriate answer from the options given below:

The energy of an electron in the first Bohr orbit of hydrogen atom is $$-2.18\times 10^{-18}\mathrm{J}$$. Its energy in the third Bohr orbit is ____________.

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : In the photoelectric effect, the electrons are ejected from the metal surface as soon as the beam of light of frequency greater than threshold frequency strikes the surface. Reason R : When the photon of any energy strikes an electron in the atom, transfer of energy from the photon to the electron takes place. In the light of the above statements, choose the most appropriate answer from the options given below :