In which of the following is the hydration energy higher than the lattice energy?

The number of values of $x$ in the interval $[0, 3\pi]$ satisfying $2 \sin^2 x + 5 \sin x - 3 = 0$ is

Three charges $2q, -q$ and $-q$ are located at the vertices of an equilateral triangle. At the centre of the triangle,

In an acute angled triangle,$\cot B \cot C + \cot A \cot C + \cot A \cot B$ is equal to

Write the resonance structures of $CO_3^{2-}$ and $HCO_3^-$.

When the coordinate axes are rotated by an angle $\tan ^{-1}\left(\frac{3}{4}\right)$ about the origin,then the equation $x^2+y^2=9$ is transformed to the equation.