If 0.5 mol of \(\mathrm{BaCl_2}\) is mixed with 0.2 mol of \(\mathrm{Na_3PO_4}\) the maximum number of mol of \(\mathrm{Ba_3PO_4}\) that can be formed is

This question uses mole concept & stoichiometry. Convert all given quantities into moles using n = given amount/molar mass, use Avogadro's number where needed to get particles, and then compare with the options; this matches option D.