The oxidation state of phosphorus in hypophosphoric acid is + _____________.

The density of a monobasic strong acid (Molar mass 24.2 g/mol) is 1.21 kg/L. The volume of its solution required for the complete neutralization of 25 mL of 0.24 M NaOH is __________ $$\times$$ 10$$^{-2}$$ mL (Nearest integer)

The normality of $$\mathrm{H}_{2} \mathrm{SO}_{4}$$ in the solution obtained on mixing $$100 \mathrm{~mL}$$ of $$0.1 \,\mathrm{M} \,\mathrm{H}_{2} \mathrm{SO}_{4}$$ with $$50 \mathrm{~mL}$$ of $$0.1 \,\mathrm{M}\, \mathrm{NaOH}$$ is _______________ $$\times 10^{-1} \mathrm{~N}$$. (Nearest Integer)

$$20 \mathrm{~mL}$$ of $$0.02\, \mathrm{M}$$ hypo solution is used for the titration of $$10 \mathrm{~mL}$$ of copper sulphate solution, in the presence of excess of KI using starch as an indicator. The molarity of $$\mathrm{Cu}^{2+}$$ is found to be ____________ $$\times 10^{-2} \,\mathrm{M}$$. [nearest integer]

Given : $$2 \,\mathrm{Cu}^{2+}+4 \,\mathrm{I}^{-} \rightarrow \mathrm{Cu}_{2} \mathrm{I}_{2}+\mathrm{I}_{2}$$

$$ \mathrm{I}_{2}+2 \mathrm{~S}_{2} \mathrm{O}_{3}^{2-} \rightarrow 2 \mathrm{I}^{-}+\mathrm{S}_{4} \mathrm{O}_{6}^{2-} $$