Aspirin ( $C X_{9} H X_{8} O X_{4}$ , molar mass $180$ g/mol) is heated with excess NaOH until it is completely converted to disodium salicylate and sodium acetate. The mass of NaOH (molar mass $40$ g/mol) consumed by $1.80 g$ of aspirin is

A $2.40 g$
B $1.20 g$
C $0.40 g$
D $0.80 g$

Answer: B

The reaction is

C X_{9} H X_{8} O X_{4} + 3 NaOH C X_{7} H X_{4} O X_{3} Na X_{2} + C X_{2} H X_{3} O X_{2} Na + 2 H X_{2} O

: one NaOH neutralises the carboxylic acid, one hydrolyses the acetyl ester (giving acetate and a phenol), and one neutralises the phenol. Moles of aspirin =

1.80/180 = 0.0100

. NaOH =

3 \times 0.0100 \times 40 = 1.20 g

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Aspirin (CX9​HX8​OX4​, molar mass 180 g/mol) is heated with excess NaOH until it is completely converted to disodium salicylate and sodium acetate. The mass of NaOH (molar mass 40 g/mol) consumed by 1.80 g of aspirin is

Answer: B

More questions on Antacids, antihistamines, analgesics, antibiotics

Aspirin ( $C X_{9} H X_{8} O X_{4}$ , molar mass $180$ g/mol) is heated with excess NaOH until it is completely converted to disodium salicylate and sodium acetate. The mass of NaOH (molar mass $40$ g/mol) consumed by $1.80 g$ of aspirin is