What Combination of Substances Will Give a Buffered Solution That $\times$

question 78

Multiple Choice

What combination of substances will give a buffered solution that has a pH of 5.05? (Assume each pair of substances is dissolved in 5.0 L of water. ) (K_b for NH₃ = 1.8 $\times$ 10^-5;K_b for C₅H₅N = 1.7 $\times$ 10^-9)

• A)1.0 mole NH₃ and 1.5 mole NH₄Cl
• B)1.5 mole NH₃ and 1.0 mole NH₄Cl
• C)1.0 mole C₅H₅N and 1.5 mole C₅H₅NHCl
• D)1.5 mole C₅H₅N and 1.0 mole C₅H₅NHCl
• E)none of these

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Definitions:

Extrinsic Eye Muscles

The external muscles that control eye movement, responsible for rotating the eyeball in various directions.

Genioglossus

A muscle in the tongue that is responsible for its movement, enabling speech, swallowing, and positioning of the tongue.

Orbicularis Oris

A complex of muscles in the lips that encircles the mouth, controlling movements such as closing, puckering, and protruding the lips.

Frontal Belly

Part of the occipitofrontalis muscle which moves the scalp, eyebrows, and forehead skin.