# chemistry

Asprin, C9H8O4, is prepared by reacting salicylic acid, C7H6O3, with acetic anhydride, C4H6O3, in the reaction
C7H6O3(s) + C4H6O3(l) -> C9H8O4(s) + C2H4O2(l)
A student is told to prepare 45.0 g of aspirin. She is also told to use a 55.0% excess of the acetic anhydride and to expect to get an 85.0% yield in the reaction. How many grams of each reactant should she use?

Can someone please give me a brief outline what I need to do to solve this?

You want 45 g aspirin. How many moles of asprin is that?

You want that number of moles/.85 of salicytic acid, and aspirin (numbermolesAspirin/.85) * 1.55 of the acetic anhydride. Think this out, repost if you have questions.

1. 👍
2. 👎
3. 👁
1. C7H6O3 (s) + C4H6O3 (l) -> C9H8O4 (s) + C2H4O2 (l)
molar masses:
salicylic acid, C7H6O3 = 138.12 g/mol
acetic anhydride, C4H6O3 = 102.09 g/mol
Asprin, C9H8O4 = 180.157 g/mol

For this problem calculate the moles of aspirin obtained from 45.0 g. This represents an 85.0% yield.

% yield = (mass aspirin produced)/(theoretical mass aspirin)](100%)

Using those numbers above, calculate the theoretical mass of aspirin needed. Once you have that number you can calculate the theoretical moles of aspirin. Use the chemical equation to determine the mass of salicylic acid needed to obtain the 45 grams.

Moles aspirin = moles salicylic acid = moles acetic anhydride.

Once you have the moles of acetic acid then you can determine the 55% excess by multiplying by 1.55(moles acetic anhydride).

1. 👍
2. 👎
2. 2 C7H6O3 + 1 C4H6O3 -> 2 C9H8O4 + H2O

45.0 g / 0.85 = 52.9 g theoretical yield.

52.9 g C9H8O4 x (1 mole / 180.2g) = 0.294 moles aspirin

0.294 moles aspirin x (2 moles C7H6O3 / 2 moles aspirin) x (138.1 g C7H6O3 / mole C7H6O3) = 40.6 g salicylic acid.

0.294 moles aspirin x (1 mole C4H6O3 / 2 moles aspirin) x (102.1 g C4H6O3 / mole C4H6O3) = 15.0 g acetic anhydride.

but you need 55% excess C4H6O3... 1.55 x 15.0 g = 23.3 g acetic anhydride

1. 👍
2. 👎
3. how'd you get 1.55g acetic anhydride?

1. 👍
2. 👎
4. jbkjkj j

1. 👍
2. 👎
5. I think the guy/girl was supposed to put .55 but accidently put a one insead of a zero and tried to figure it out like that. The actual answer is:
0.55 x 15.0 g = 8.25 g acetic anhydride

1. 👍
2. 👎

## Similar Questions

1. ### Chemestry

Aspirin (C9H8O4) is synthesized by reacting salicylic acid (C7H6O3) with acetic anhydride (C4H6O3). The balanced equation is given below. C7H6O3 + C4H6O3 C9H8O4 + HC2H3O2 (a) What mass of acetic anhydride is needed to completely

2. ### chem

Aspirin, C9H8O4, is produced from salicylic acid, C7H6O3, and acetic anhydride, C4H6O3: C7H6O3 + C4H6O3 --> C9H8O4 + HC2H3O2 a. How much salicylic acid is required to produce 1.5 x 10^2 kg of aspirin, assuming that all of the

3. ### chemistry

A student prepared aspirin (C9H8O4) in a laboratory experiment using the following reaction. C7H6O3 + C4H6O3 C9H8O4 + HC2H3O2 The student reacted 2.00 g salicylic acid (C7H6O3) with 2.67 g acetic anhydride (C4H6O3). The yield was

4. ### school

What is the pH of 0.1 M formic acid solution? Ka=1.7„e10-4? What is the pH value of buffer prepared by adding 60 ml of 0.1 M CH3COOH to 40 ml of a solution of 0.1 M CH3COONa? What is the pH value of an acetate buffer (pK=4.76)

1. ### Chemistry

Aspirin is prepared by heating salicylic acid, C7H6O3, with acetic anhydride, C4H603. The other product produced is acetic acid, C2H402. C7H6O3+C4H6)3->C9H8O4+C2H4O2 What is the theoretical yield in grams of aspirin, C9H8O4, when

2. ### O Chemistry

In the reaction p-aminophenol + acetic anhydride --> acetaminophen , 4.5 ml of water is added into the flask with the p-aminophenol and acetic anhydride at the beginning of the experiment. What is the purpose of this water?

3. ### Chemistry

Calculate the theoretical yield of aspirin to be obtained in this experiment, starting with 2.0 g of salicylic acid and 5.0 ml of acetic acid anhydride (density = 1.08 g/ml).

4. ### Chemistry

Asprin(acteyl salicylic acid) can be synthesized by reacting acetic anhydride with salicylic acid. Assume the reaction was run and 1.75 grams of a solid product was obtained. Recrystalization of the 1.75 g mixture yielded 1.50 g

1. ### Chemistry

In the synthesis of asprin we react salicylic acid (HOOCC6H4OH) with acetic anhydride (C4H6O3) . The unbalanced chemical equation is: HOOCC6H4OH + C4H6O3 --> HOOCC6H4O2C2H3 + H2O If we mix together 28.2 g of salicylic acids with

2. ### Organic Chemistry

An impure sample contains 0.95g of benzoic acid and 0.05 of salicylic acid. Solubilities in water of the two compounds are given in the following table. Solubility at 20 degrees (g/10mL) benzoic acid: 0.029 salicylic acid: 0.22

3. ### Chemistry

Aspirin, C9H8O4 , is produced through the following reaction of salicylic acid, C7H6O3, and acetic anhydride, C4H6O3: C7H6O3(s) + C4H6O3(l) ---> C9H8O4(s) + HC2H3O2(l) A. What mass of aspirin (kg) could be produced from 75.0 mol

4. ### Chemistry

If 0.150 moles of salicylic acid and execs acetic anhydride are used during a synthesis of aspirin, how many grams of aspirin will be obtained if the reaction gives a 38% yield?