1g sample of H₂O₂ solution containing x% H₂O₂ by weight requires x mL of K₂Cr₂O₇ solution for
complete oxidation under acidic conditions. The molarity of K₂Cr₂O₇ solution is —— .

3H₂O₂ + K₂Cr₂O₂ + 4H₂SO₄ $\to$K₂SO₄ + Cr₂(SO₄)₃ + 7H₂O + 3O₂ 
M eq of H₂O₂ = m eq of K₂Cr₂O₇

$\begin{array}{r}100\mathrm{g}\text{ of }{\mathrm{H}}_2{\mathrm{O}}_2\text{ solution contains }x\text{ gof }{\mathrm{H}}_2{\mathrm{O}}_2\\ =\text{ Weightof }{\mathrm{H}}_2{\mathrm{O}}_2\\ m\text{ Eq of }{\mathrm{H}}_2{\mathrm{O}}_2=\frac{\text{ Weightof }{\mathrm{H}}_2{\mathrm{O}}_2\times {10}^3}{E{\mathrm{EwHH}}_2{\mathrm{O}}_2}\\ =\frac{5.1x}{100}\times \frac{1}{17}\times {10}^3=3xmEq\\ {\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}\equiv {\mathrm{H}}_2{\mathrm{O}}_2\\ mEq\equiv mEq\\ N_1{V}_1\left(mL\right)\equiv 3x\\ N_1\times xmL=3x\\ N\left({\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7\right)=3\mathrm{N}\\ M\left(K_2{\mathrm{Cr}}_2{\mathrm{O}}_7\right)=\frac{\mathrm{N}}{n}=0.5M\\ \end{array}$