Calculate the Minimum Concentration of Cr³⁺ That Must Be Added

question 114

Multiple Choice

Calculate the minimum concentration of Cr³⁺ that must be added to 0.095 M NaF in order to initiate a precipitate of chromium(III) fluoride. (For CrF₃ , K_sp = 6.6 * 10^-11.)

• A) 0.023 M
• B) 0.032 M
• C) 7.7 * 10^-8 M
• D) 2.9 * 10^-9 M
• E) 6.9 * 10^-10 M

---

Definitions:

Delphi Technique

A structured communication technique or method, which relies on a panel of experts to forecast or make decisions through rounds of anonymous questionnaires.

Rational Decision-Making Technique

An approach to decision-making characterized by a systematic, logical evaluation of alternatives.

Punctuated Equilibrium Model

A theory suggesting that evolutionary development is marked by long periods of stability, punctuated by short, significant changes that result in major transformations.

Expectancy Theory

Theory that holds that people will choose certain behaviors over others with the expectation of a certain outcome.