A PH 956 Buffer Was Prepared by Mixing 2

question 56

Multiple Choice

A pH 9.56 buffer was prepared by mixing 2.00 moles of ammonia (K_b for ammonia is 1.8 × 10^-5) and 1.00 mol of ammonium chloride in water to form a solution with a volume of 1.00 L.To a 200.0 mL aliquot of this solution was added 10.0 mL of 10.0 M aqueous sodium hydroxide.What was the resulting pH?

• A)9.28
• B)9.56
• C)9.95
• D)10.50
• E)13.7

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Definitions:

D-Arabinose

A naturally occurring pentose sugar, which is a component of many polysaccharides and glycoproteins.

D-Xylose

A sugar molecule classified as an aldopentose, which means it has five carbon atoms and contains an aldehyde functional group.

Haworth Structure

A way of representing cyclic sugars that emphasizes their ring structure, useful in carbohydrate chemistry.

α-D-Glucopyranose

A cyclic form of glucose that is a building block of many carbohydrates and polysaccharides.