Explore BrainMass

Explore BrainMass

    Multiple choice questions on energy and temperature related reactions

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    If ΔG is negative, a reaction is spontaneous in the forward direction. A reaction that is not spontaneous at low temperature can become spontaneous at high temperature if ΔH is ________ and ΔS is ________.

    a. -, -
    b. +, +
    c. +, 0
    d. -, +
    e. +, -

    Which one of the following statements is true about the equilibrium constant for a reaction if ΔG° for the reaction is negative?

    a. K = 1
    b. K > 1
    c. More information is needed.
    d. K = 0
    e. K < 1

    Which element is oxidized in the reaction below?
    Fe(CO)5(l) + 2HI(g) Fe(CO)4I2(s) + CO(g) + H2(g)

    a. Fe
    b. C
    c. H
    d. O
    e. I

    Which substance is the reducing agent in the reaction below?
    Pb + PbO2 + 2H2SO4 2PbSO4 + 2H2O

    a. H2O
    b. PbO2
    c. PbSO4
    d. Pb
    e. H2SO4

    What is the oxidation state of manganese in manganese dioxide?

    a. +7
    b. +2
    c. +1
    d. +3
    e. +4

    What is the coefficient of the permanganate ion when the following equation is correctly balanced?
    MnO4- + Br- Mn2+ + Br2 (acidic solution)

    a. 3
    b. 1
    c. 5
    d. 2
    e. 4

    The balanced half-reaction in which dichromate ion is reduced to chromium (III) ion is a __________ process.

    a. four-electron
    b. six-electron
    c. two-electron
    d. three-electron
    e. twelve-electron

    Which of the following transformations could take place at the cathode of an electrochemical cell?

    -> HNO2
    b. Br2 -> BrO3-
    c. HSO4- -> H2SO3
    d. Mn2+ _> MnO4-
    e. MnO2 -> MnO4-

    © BrainMass Inc. brainmass.com March 4, 2021, 7:03 pm ad1c9bdddf

    Solution Preview

    Question 2

    Answer is (e). For any reaction to be spontaneous free energy should be negative. So for a reaction at low to become spontaneous enthalpy should be +ve and entropy should be -ve to male free energy negative

    Question 3

    Answer is ...

    Solution Summary

    The solutions provide answers to a variety of multiple choice questions relating to spontaneous reactions, oxidization, reducing agents, etc.