Solvay process is used in the manufacture of

Match the items of column $I$ with column $II$. Select the correct option from the following:

Column $I$	Column $II$
$(a)$ $XX-XO$ method of sex determination	$(i)$ Turner's syndrome
$(b)$ $XX-XY$ method of sex determination	$(ii)$ Female heterogametic
$(c)$ Karyotype-$45$	$(iii)$ Grasshopper
$(d)$ $ZW-ZZ$ method of sex determination	$(iv)$ Female homogametic

The molecular formula of diphenylmethane is $C_{13}H_{12}$. How many structural isomers are possible when one of the hydrogen atoms is replaced by a chlorine atom?

Which of the following solutions has osmotic pressure nearer to that of an equimolar solution of $K_4[Fe(CN)_6]$?

If the direction ratios $(l, m, n)$ of two lines satisfy the equations $l+m+n=0$ and $mn-2ln+lm=0$,then the angle between the lines is