You Need to Use KH₂PO₄ and K₂HPO₄ to Prepare a Buffer

question 93

Multiple Choice

You need to use KH₂PO₄ and K₂HPO₄ to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H₃PO₄) , K_a2 = 6.2 × 10^-8.

• A) [base]/[acid] = 1.75
• B) [base]/[acid] = 1.27
• C) [base]/[acid] = 1.24
• D) [base]/[acid] = 0.79
• E) [base]/[acid] = 0.57

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Definitions:

Internal Rate of Return Method

A capital budgeting method that calculates the return on investment by setting the net present value of cash flows equal to zero.

Present Value

Today's worth of a forthcoming sum of money or series of cash payments, considering a designated rate of return.

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The process of evaluating and comparing potential investments or expenditures to determine their profitability and financial impact on the business.

Net Present Value Method

A method of evaluating the feasibility of projects or investments by calculating their net present value using a discount rate.