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

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