Consider the following reactions.
\(Na_{2}B_{4}O_{7} \xrightarrow{\Delta}\) \(2 X+Y\)
\(CuSO_{4} + Y \xrightarrow{Non-Luminous flame} Z + SO_{3}\)
\(2Z + 2X + Carbon \xrightarrow{Luminous flame} 2Q + Na_{2}B_{4}O_{7} + CO\)
The oxidation states of Cu in Z and Q, respectively are:

Consider the following cases of standard enthalpy of reaction \(\left(\Delta \mathrm{H}_{\mathrm{r}}^{\circ}\right.\) in \(\left.\mathrm{kJ} \mathrm{mol}{ }^{-1}\right)\)
\(\mathrm{C}_2 \mathrm{H}_6(\mathrm{~g})+\frac{7}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow 2 \mathrm{CO}_2(\mathrm{~g})+3 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) \Delta \mathrm{H}_1^{\circ}=-1550 \)
\( \mathrm{C} \text { (graphite) }+\mathrm{O}_2(\mathrm{~g}) \rightarrow \mathrm{CO}_2(\mathrm{~g}) \quad \Delta \mathrm{H}_2^{\circ}=-393.5 \)
\( \mathrm{H}_2(\mathrm{~g})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow \mathrm{H}_2 \mathrm{O}(\mathrm{l}) \quad \Delta \mathrm{H}_3^{\circ}=-286\)
The magnitude of \(\Delta \mathrm{H}_{f \mathrm{C}_2 \mathrm{H}_6(\mathrm{~g})}^{\circ}\) is _______ \(\mathrm{kJ} \mathrm{mol}{ }^{-1}\) (Nearest integer).

The molecular geometry of \(S\,F _{6}\) is octahedral. What is the geometry of \(S\,F _{4}\) (including lone pair(s) of electrons, if any)?

Which of the following statements is correct

Given below are two statements: one is labelled as Assertion \((A)\) and the other is labelled as Reason \((R)\). Assertion \((A)\): The total number of geometrical isomers shown by \(\left[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{+}\)complex ion is three Reason \((R)\): \(\left[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{+}\)complex ion has an octahedral geometry. In the light of the above statements, choose the most appropriate answer from the options given below :

A sample of \(NaClO_3\) is converted by heat to \(NaCl\) with a loss of \(0.16\, g\) of oxygen. The residue is dissolved in water and precipitated as \(AgCl\). The mass of \(AgCl\) (in \(g\)) obtained will be (Given: Molar mass of \(AgCl = 143.5\, g\,mol^{-1}\) )

Which of the following statement is not correct?

A passenger train of length \(60\, m\) travels at a speed of \(80\, km/hr\). Another freight train of length \(120\, m\) travels at a speed of \(30\, km/hr\). The ratio of times taken by the passenger train to completely cross the freight train when: \((i)\) they are moving in the same direction, and \((ii)\) in the opposite directions is

Let in a right angled triangle, the smallest angle be \(\theta\). If a triangle formed by taking the reciprocal of its sides is also a right angled triangle, then \(\sin \theta\) is equal to:

The value of \(\left(\frac{1+\sin \frac{2 \pi}{9}+i \cos \frac{2 \pi}{9}}{1+\sin \frac{2 \pi}{9}-i \cos \frac{2 \pi}{9}}\right)^3\) is

If \(I_{m, n}=\int_{0}^{1} x^{m-1}(1-x)^{n-1} d x,\) for \(m, n \geq 1\) and \(\int_{0}^{1} \frac{x^{m-1}+x^{n-1}}{(1+x)^{m+n}} d x=\alpha I_{m, n}, \alpha \in R,\) then \(\alpha\) equals .... .

A Copper \((Cu)\) rod of length \(25\, {cm}\) and cross- sectional area \(3\, {mm}^{2}\) is joined with a similar Aluminium \((Al)\) rod as shown in figure. Find the resistance of the combination between the ends \(A\) and \(B\) (in \({m} \Omega\)) (Take Resistivity of Copper \(=1.7 \times 10^{-8}\, \Omega \,{m}\), Resistivity of Aluminium \(=2.6 \times 10^{-8}\, \Omega \,{m}\) )

A cell \(E _{1}\) of \(emf 6 V\) and internal resistance \(2 \Omega\) is connected with another cell \(E _{2}\) of \(emf 4 V\) and internal resistance \(8 \Omega\) (as shown in the figure). The potential difference across points \(X\) and \(Y\) is............ \(V\)