Among the following, which one is correct for brown ring test?

Identify the number of reactions among the following which can result in at least one yellow-colored precipitate as the product.

i. ${\mathrm{Pb}}^{+2}+\mathrm{KI}\to$

ii. ${\mathrm{Pb}}^{+2}+{\mathrm{H}}_2{\mathrm{SO}}_4\to$

iii. ${\mathrm{Al}}^{+3}+\mathrm{NaOH}\to$

iv. ${\mathrm{Mg}}^{+2}+{\mathrm{Na}}_2{\mathrm{HPO}}_4\to$

v. ${\mathrm{Pb}}^{+2}+{\mathrm{K}}_2{\mathrm{CrO}}_4\to$

vi. ${\mathrm{I}}^{-}+{\mathrm{AgNO}}_3\to$

vii. ${\mathrm{SO}}_4^{-2}+{\mathrm{BaCl}}_2\to$