2. Solved Papers
  3. BCECE Engineering

BCECE Engineering BCECE Engineering Solved Paper-2013

  • question_answer
    A quantity of electrical charge that brings about the deposition of 4.5 g Al from \[\text{A}{{\text{l}}^{\text{3+}}}\]at the cathode will also produce the following volume 3t (STP) of \[{{\text{H}}_{2}}(g)\] from \[{{H}^{+}}\]at the cathode

    A) 44.8 L              

    B)        22.4 L    

    C)        11.2 L              

    D)        5.6 L

    Correct Answer: D

    Solution :

    \[2{{H}^{+}}+2{{e}^{-}}\xrightarrow{{}}{{H}_{2}}\] \[A{{l}^{3}}+3{{e}^{-}}\xrightarrow{{}}Al\] \[\frac{w({{H}_{2}})}{w(Al)}=\frac{E({{H}_{2}})}{E(Al)}=\frac{1}{9}\]                 \[w({{H}_{2}})=4.5\times \frac{1}{9}=0.5g=\frac{1}{4}mol\,{{H}_{2}}\] \[=\frac{22.4}{4}=5.6\,L\,{{H}_{2}}\]at STP


You need to login to perform this action.
You will be redirected in 3 sec spinner