Which of the following is a true acidic anhydride?

Crystals of which pair are isomorphous?

Both $[Ni(CO)_4]$ and $[Ni(CN)_4]^{2-}$ are diamagnetic. The hybridisations of nickel in the complexes,respectively are

If $3 \cos x \neq 2 \sin x$,then the general solution of $\sin^2 x - \cos 2x = 2 - \sin 2x$ is

The equation of a pair of lines is given by a second-degree homogeneous equation. If one of them is perpendicular to the line $x+2y+7=0$ and the other line is parallel to the line $3x+4y+5=0$,then the equation of that pair of lines is:

Which of the following is commonly used in a desiccator in the laboratory?