The reaction between and to form complex was investigated under three conditions

CHEMISTRY · Subjective · ISC · Chemistry · Chemical Kinetics · Arrhenius equation

Problem

The reaction between $ \mathrm{Fe}^{3+}(\mathrm{aq})

and

\mathrm{SCN}^{-}(\mathrm{aq})

to form

\mathrm{FeSCN}^{2+}$ complex was investigated under three conditions. Condition |

[\mathrm{Fe}^{3+}]_0

(

\text{mol}\,\text{L}^{-1}

) |

[\mathrm{SCN}^{-}]_0

(

\text{mol}\,\text{L}^{-1}

) | Temperature (

^\circ\text{C}

) X |

1.0 \times 10^{-3}\,\text{mol}\,\text{L}^{-1}

1.0 \times 10^{-3}\,\text{mol}\,\text{L}^{-1}

25\,^\circ\text{C}

Y |

2.0 \times 10^{-3}\,\text{mol}\,\text{L}^{-1}

1.0 \times 10^{-3}\,\text{mol}\,\text{L}^{-1}

15\,^\circ\text{C}

Z |

1.0 \times 10^{-3}\,\text{mol}\,\text{L}^{-1}

1.0 \times 10^{-3}\,\text{mol}\,\text{L}^{-1}

35\,^\circ\text{C}

Determine which condition (X, Y, or Z) produces the slowest initial rate, and give a concise explanation referencing the key rate-controlling factor.