A compound '$$\mathrm{X}$$' when treated with phthalic anhydride in presence of concentrated $$\mathrm{H}_{2} \mathrm{SO}_{4}$$ yields '$$\mathrm{Y}$$'. '$$\mathrm{Y}$$' is used as an acid/base indicator. '$$\mathrm{X}$$' and '$$\mathrm{Y}$$' are respectively

Henry Moseley studied characteristic X-ray spectra of elements. The graph which represents his observation correctly is

Given $$v=$$ frequency of $$\mathrm{X}$$-ray emitted

Z = atomic number

Given below are two statements:

Statement I : In redox titration, the indicators used are sensitive to change in $$\mathrm{pH}$$ of the solution.

Statement II : In acid-base titration, the indicators used are sensitive to change in oxidation potential.

In the light of the above statements, choose the most appropriate answer from the options given below

For a good quality cement, the ratio of lime to the total of the oxides of $$\mathrm{Si}, \mathrm{Al}$$ and $\mathrm{Fe}$ should be as close as to :