What precise mass of is required to accurately prepare mL of a standard solution for use as a primar — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

The equivalent weight ( $E$ ) of $K_2Cr_2O_7$ in an acidic medium is derived from its n-factor of 6, so $E = M/6 = 294 / 6 = 49$ g/eq. The general equation for Normality ( $N$ ) is (Mass / $E$ ) $\times$ (1000 / Volume in mL). Inputting the values: $0.2 = (Mass / 49) \times (1000 / 50) \Rightarrow 0.2 = (Mass / 49) \times 20 \Rightarrow Mass = 0.2 \times 49 / 20 = 9.8 / 20 = 0.49$ g.