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Coefficients or electrons needed to balance a redox equation

This type of question, asked 3 times: 9 May 2023 S1, 10 May 2024 S1, 26 Apr 2025 S1. All 3 questions below, oldest first.

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  1. Question 1

    9 May 2023 S1

    73
    What is the value of xx and yy in order to balance following redox reaction? xCuO+yNH3→xCu+N2+xH2Ox\text{CuO} + y\text{NH}_3 \rightarrow x\text{Cu} + \text{N}_2 + x\text{H}_2\text{O}

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  2. Question 2

    10 May 2024 S1

    68
    What is the value of x to balance: Mn(aq)2++xClO3−(aq)→MnO2(s)+xClO2(aq)\text{Mn}^{2+}_{(aq)}+x\text{ClO}_3^-\text{(aq)}\to\text{MnO}_2\text{(s)}+x\text{ClO}_2\text{(aq)}

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  3. Question 3

    26 Apr 2025 S1

    94
    In the equation, BiO3−+6H++xe−→Bi3++3H2OBiO_{3}^{-}+ 6H^{+}+xe^{-}\rightarrow Bi^{3+}+ 3H_{2}O, what is the value of xx ?

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