Which of the following acids possesses oxidising,reducing,and complex-forming properties?

The floral formula (image) is that of

In the Young's double slit experiment using a monochromatic light of wavelength $\lambda$,the path difference (in terms of an integer $n$) corresponding to any point having half the peak intensity is :-

Amongst the given taxonomic aids,how many are associated with the preservation of specimens? Monograph,Flora,Key,Museums,Botanical Gardens,Catalogue,Herbarium,Manual

The eccentricity of the conic $\frac{5}{r}=2+3 \cos \theta+4 \sin \theta$ is

If $\overline{a}, \overline{b}, \overline{c}$ are non-coplanar unit vectors such that $\overline{a} \times (\overline{b} \times \overline{c}) = \frac{\overline{b} + \overline{c}}{\sqrt{2}}$,then the angle between $\overline{a}$ and $\overline{b}$ is