What is the $IUPAC$ name of the following compound?

White vitriol is:

$\int_{-1}^1 \frac{\cosh x}{1+e^{2 x}} d x$ is equal to :

If $g(x) = \int_0^x \cos^4 t \, dt$,then $g(x + \pi)$ equals

If $m_1, m_2, m_3$ and $m_4$ are respectively the magnitudes of the vectors $\overrightarrow{a}_1=2 \hat{i}-\hat{j}+\hat{k}$,$\overrightarrow{a}_2=3 \hat{i}-4 \hat{j}-4 \hat{k}$,$\overrightarrow{a}_3=\hat{i}+\hat{j}-\hat{k}$ and $\overrightarrow{a}_4=-\hat{i}+3 \hat{j}+\hat{k}$,then the correct order of $m_1, m_2, m_3$ and $m_4$ is

Which of the following halogens undergoes disproportionation in water?