What Is the Approximate Concentration of Free Fe²⁺ Remaining at Equilibrium

question 27

Multiple Choice

What is the approximate concentration of free Fe²⁺ remaining at equilibrium in a solution prepared by mixing 5.0 mL of 0.10 M FeSO₄ with 5.0 mL of 2.0 M KCN? [The net formation constant for the hexacyanoferrate(II) ion is 1 × 10³⁷.]

• A) 3 × 10^-22 M
• B) 7 × 10^-30 M
• C) 4 × 10^-38 M
• D) 5 × 10^-37 M
• E) 4 × 10^-40 M

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Definitions:

Unconscious

Refers to the part of the mind that contains thoughts, memories, and desires not within the sphere of current awareness but that nonetheless influence behavior.

Preconscious

A part of the mind that contains thoughts, feelings, and memories that are not currently in conscious awareness but can easily be brought to consciousness.

Conscious

The state of being aware of and responsive to one's surroundings and internal thoughts and feelings.

Superego

In psychoanalytic theory, the part of the personality that acts as the moral center, enforcing ethical conduct and striving for perfection.