Homework Solution: The oxidation of Cr3+ to CrO42– can be accomplished using Ce4+ in a buffered solution. The…

    The oxidation of Cr3+ to CrO42– can be accomplished using Ce4+ in a buffered solution. The following data were obtained:
    Relative Initial Rate [Ce4+]0 [Ce3+]0 [Cr3+]0
    1 2.0 × 10–3 1.0 × 10–2 3.0 × 10–2
    2 4.0 × 10–3 2.0 × 10–2 3.0 × 10–2
    4 4.0 × 10–3 1.0 × 10–2 3.0 × 10–2
    16 8.0 × 10–3 2.0 × 10–2 6.0 × 10–2
    Determine the order in the rate law of the species Ce3+. I don't understand this question at all. Why is the answer -1?

    Expert Answer

    Answer

    The oxidation of Cr3+ to CrO42– can be genteel using Ce4+ in a buffered disintegration. The subjoined basis were obtained:

    Relative
    Initial Objurgate
    [Ce4+]0 [Ce3+]0 [Cr3+]0
    1 2.0 × 10–3 1.0 × 10–2 3.0 × 10–2
    2 4.0 × 10–3 2.0 × 10–2 3.0 × 10–2
    4 4.0 × 10–3 1.0 × 10–2 3.0 × 10–2
    16 8.0 × 10–3 2.0 × 10–2 6.0 × 10–2

    Determine the direct in the objurgate legislation of the genius Ce3+.

    I don’t learn this interrogation at whole. Why is the solution -1?

    Expert Solution

    Answer

    let the objurgate (r)= K[Ce+4]a [ Ce+3]b [Cr+3]c, a, b and c are directs with i-elation to Ce+4, Ce+3 and Cr+3 i-elationively. K is the objurgate constant

    from 2nd basis sharp-end, 2= K[ 4*10-3]a* [ 2*10-2]b* [3*10-2]c ,   (1)

    from the 3rd basis sharp-end, 4= K[ 4*10-3]a* [ 1*10-2]b* [3*10-2]c ,   (2)

    Eq.2/Eq.1= 2= (1/2) b= 2-b= 2 , b=-1, the direct of reaction with i-elation to Ce+3.