250 ML of a Hydrofluoric Acid Solution of Unknown Concentration

question 73

Multiple Choice

25.0 mL of a hydrofluoric acid solution of unknown concentration is titrated with 0.200 M NaOH. After 20.0 mL of the base solution has been added, the pH in the titration flask is 3.00. What was the concentration of the original hydrofluoric acid solution. [K_a(HF) = 7.1 * 10^-4]

• A) 0.39 M
• B) 0.27 M
• C) 0.16 M
• D) 2.4 M
• E) 0.23 M

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Definitions:

Excess Reserves

The banks' reserves over and above the required minimum that they choose to hold rather than loan out.

Depositors

People or organizations that deposit their funds into a bank to secure them and gain interest as time passes.

Borrowers

Individuals or entities that take funds from a lender under the agreement to pay back the principal amount along with interest.

Required Reserves

The dollar amount of reserves a bank is obligated by regulation to hold as cash in the bank’s vault or on account at the Fed.