The exact volumes of \(1\, M\, NaOH\) solution required to neutralise \(50 \,mL\) of \(1 \,M \,H _{3} PO _{3}\) solution and \(100\, mL\) of \(2 \,M\, H _{3} PO _{2}\) solution, respectively, are :

Number of moles and number of molecules in \(1.4187\) L of \(SO_2\) at STP respectively are:

Which one of the following arrangements represents the correct order of the proton affinity of the given species

Identify the correct statements:
A. Hydrated salts can be used as primary standard.
B. Primary standard should not undergo any reaction with air.
C. Reactions of primary standard with another substance should be instantaneous and stoichiometric.
D. Primary standard should not be soluble in water.
E. Primary standard should have low relative molar mass.
Choose the correct answer from the options given below :

The \('f'\) orbitals are half and completely filled, respectively in lanthanide ions .... (Given: Atomic no. \(Eu, 63; Sm , 62 ; Tm , 69 ; Tb\), \(65 ; Yb , 70 ; Dy , 66]\)

For \(\mathrm{A}_2+\mathrm{B}_2 \rightleftharpoons 2 \mathrm{AB}\)
\(\mathrm{E}_{\mathrm{a}}\) for forward and backward reaction are 180 and \(200 \mathrm{~kJ} \mathrm{~mol}^{-1}\) respectively
If catalyst lowers \(\mathrm{E}_{\mathrm{a}}\) for both reaction by \(100 \mathrm{~kJ} \mathrm{~mol}^{-1}\).
Which of the following statement is correct?

Some \(\mathrm{CO}_2\) gas was kept in a sealed container at a pressure of 1 atm and at 273 K . This entire amount of \(\mathrm{CO}_2\) gas was later passed through an aqueous solution of \(\mathrm{Ca}(\mathrm{OH})_2\). The excess unreacted \(\mathrm{Ca}(\mathrm{OH})_2\) was later neutralized with 0.1 M of 40 mL HCl . If the volume of the sealed container of \(\mathrm{CO}_2\) was \(x\), then \(x\) is ________ \(\mathrm{cm}^3\) (nearest integer).
[Given : The entire amount of \(\mathrm{CO}_2(\mathrm{~g})\) reacted with exactly half the initial amount of \(\mathrm{Ca}(\mathrm{OH})_2\) present in the aqueous solution.]

Let \(f(x)=\int x^3 \sqrt{3-x^2} d x\). If \(5 f(\sqrt{2})=-4\), then \(f(1)\) is equal to

Ratio of radius of gyration of a hollow sphere to that of a solid cylinder of equal mass, for moment of Inertia about their diameter axis \(A B\) as shown in figure is \(\sqrt{\frac{8}{x}}\). The value of \(x\) is _______.

A hemispherical vessel is completely filled with a liquid of refractive index \(\mu\). A small coin is kept at the lowest point \((\mathrm{O})\) of the vessel as shown in figure. The minimum value of the refractive index of the liquid so that a person can see the coin from point E (at the level of the vessel) is _______.

A thin glass plate of thickness is \(\frac{{2500}}{3}\,\lambda \) (\(\lambda \) is wavelength of light used) and refractive index \(\mu  = 1.5\) is inserted between one of the slits and the screen in Young's double slit experiment. At a point on the screen equidistant from the slits, the ratio of the intensities before and after the introduction of the glass plate is

For the compounds \(CH_3Cl, CH_3Br, CH_3I\) and \(CH_3F\), the correct order of increasing \(C-\) halogen bond length is

Based on the given figure, the number of correct statement/s is/are \(........\). \(A.\) Surface tension is the outcome of equal attractive and repulsion forces acting on the liquid molecule in bulk. \(B.\) Surface tension is due to uneven forces acting on the molecules present on the surface. \(C.\) The molecule in the bulk can never come to the liquid surface. \(D.\) The molecules on the surface are responsible for vapour pressure if the system is a closed system.