Question

Which of the following does not/do not represent the correct equivalent mass of $Cr_{2}O_{7}^{2-}$ in the reaction
$Cr_{2}O_{7}^{2-}+14H^{+}+6e^{-} \rightarrow 2Cr^{3+}+7H_{2}O $ ?

• A. The molar mass of dichromate
• B. One third of the molar mass of dichromate
• C. One sixth of the molar mass of dichromate
• D. One half of the molar mass of dichromate

Answer 1

Answer: (A), (B), (D)

$\therefore E_{ Cr _{2} O _{7}^{2-}}=\frac{{ }^{M} Cr _{2} O _{7}^{2-}}{6}$

${\left[ Cr _{2}^{6+} \longrightarrow 2 Cr ^{3+}+6 e^{-}\right]}$