Which of the Following Weak Acids Would Make the Best

question 1

Multiple Choice

Which of the following weak acids would make the best buffer at pH = 5.0?

• A) acetic acid (K_a = 1.74 × 10−⁵, pK_a = 4.76)
• B) H₂PO₄− (K_a = 1.38 × 10−⁷, pK_a = 7.20)
• C) bicarbonate (K_a = 6.3 × 10−¹¹, pK_a = 10.24)
• D) tris-hydroxymethyl aminomethane (K_a = 8.32 × 10−⁹, pK_a = 8.07)
• E) lactic acid (K_a = 1.38 × 10−⁴, pK_a = 3.86)

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Definitions:

Constant Returns to Scale

A situation in which the proportionate increase in inputs leads to an equal proportionate increase in outputs, meaning costs and outputs scale equally as production expands.

Diseconomies of Scale

A situation where a business's cost per unit increases as it produces more items, due to inefficiencies that arise with scaling up production.

Plant Size

Refers to the physical capacity or output level of a manufacturing or production facility.

Output Levels

The quantity of goods or services produced by a company, sector, or economy in a given period of time.