In the two elements, \({ }_{Z_1} A^{M_1}\) and \({ }_{z_2} B^{M_2}\), the following relations are true. \(M_1 \neq M_2\) and \(Z_1 \neq Z_2\) but \(M_1-Z_1=M_2-Z_2\). These elements are ( \(M\) is atomic weight, \(Z\) is atomic number)

Calculate the emf of the cell \(\mathrm{Cu}(s)\left|\mathrm{Cu}^{2+}(a q)\right|\left|\mathrm{Ag}^{+}(a q)\right| \mathrm{Ag}(s)\) Given \(E_{\mathrm{Cu}^{2+} / \mathrm{Cu}}^0=+0.34 \mathrm{~V}, E_{\mathrm{Ag}^{+} / \mathrm{Ag}}^0=0.80 \mathrm{~V}\)

When \(10 \mathrm{~g}\) of methane is completely burnt in oxygen, the heat evolved is \(560 \mathrm{~kJ}\). What is the heat of combustion (in \(\mathrm{kJ} \mathrm{mol}^{-1}\) ) of methane?

Which of the following reactions is used for Mond's process of metal refining?

Which one of the following is an emulsion?

Two statements are given below. Statement I : Molten NaCl is electrolysed using Pt electrodes. \(\mathrm{Cl}_2\) is liberated at anode. Statement II : Aqueous \(\mathrm{CuSO}_4\) is electrolysed using Pt electrodes. \(\mathrm{O}_2\) is liberated at cathode. The correct answer is

An oxoacid of phosphorus ' X ' reduces silver nitrate solution to metallic silver and gets oxidised to another compound \(\mathrm{Y}. \mathrm{X}\) and Y respectively are.

The products C and D are

Let \(f: \mathrm{A} \rightarrow \mathrm{B}\) be defined as \(f(x)=\frac{1}{2}-\tan \left(\frac{\pi x}{2}\right)\) and \(g: \mathrm{B} \rightarrow \mathrm{C}\) be defined \(g(x)=\sqrt{3+4 x-4 x^2}\). If A, B, C are subsets of \(\mathbb{R}\) and \(f\) is an onto function then the range of the function \(f(x)\) is

The smaller side of the rectangle with the largest area, that can be inscribed inside a semi-circle of radius $2$ units is of length

In the triangle with vertices at \(A(6,3), B(-6,3)\) and \(C(-6,-3)\), the median through \(A\) meets \(B C\) at \(P\), the line \(A C\) meets the \(x\)-axis at \(Q\), while \(R\) and \(S\) respectively denote the orthocentre and centroid of the triangle. Then the correct matching of the coordinates of points in List-I to List-II is \(\begin{array}{llll} & \text { List-I } & & \text { List-II } \ \text { (i) } & P & \text { (A) } & (0,0) \ \text { (ii) } & Q & \text { (B) } & (6,0) \ \text { (iii) } & R & \text { (C) } & (-2,1) \ \text { (iv) } & S & \text { (D) }(-6,0) \ & & \text { (E) }(-6,-3) \ & & \text { (F) }(-6,3)\end{array}\) (i) (ii) (iii) (iv)

The electron affinity values of elements \(A, B, C\) and \(D\) are respectively \(-135,-60,-200\) and \(-348 \mathrm{~kJ} \mathrm{~mol} \mathrm{~m}^{-1}\). The outer electronic configuration of element \(B\) is

The number of ways in which 6 boys and 4 girls can be arranged in a row such that between any two girls there must be exactly 2 boys is