All categories

3 years ago

Please help with an easy percentage yield question ASAP!!! Would really appreciate!

Chemistry

1 answer:

Brut [27]3 years ago

7 0

Answer:

The mass percentage yield is 85%

Explanation:

Step 1: The balanced equation

2 C7H6O3 + (CH3CO)2CO → 2 C9H8O4 + H20

Step 2: Given data

mass of salicylic acid = 1.03 grams

Volume of acetic anhydride = 2.00 mL = 2*10^-3 L

The product is 1.16 g aspirin synthesized

Molar mass of salicylic acid = 138.12 g/mole

Molar mass of aspirin = 180.16 g/mole

Density of acetic anhydride = 1.0820 g/mL

Step 3: Calculated moles of salicylic acid

Number of moles of salicylic acid = mass of salicylic acid / Molar mass of salicylic acid

Number of moles of salicylic acid = 1.03 grams / 138.12 g/mole

Number of moles of salicylic acid =0.0075 moles

Step 4: Calculated mass acetic anhydride

mass of acetic anhydride = 1.0820 g/mL * 2 mL = 2.164 grams

Step 5: Calculate number of moles of acetic anhydride

Number of moles = 2.164 grams / 102.09 g/moles

Number of moles = 0.0212 moles

Step 6: Find amount of reacting moles

C7H6O3 is the limiting reactant, there will react 0.0075 moles

Since for 2 moles C7H6O3 consumed, we need 1 mole of (CH3CO)2CO to produce 2 moles of C9H804

So for 0.0075 moles C7H6O3 consumed, we produce 0.0075 moles of C9H8O4

Step 7: Calculate mass of aspirin

mass of aspirin = 0.0075 moles * 180 g/mole = 1.35 grams

Step 8: Calculate the mass percentage yield

(1.16 grams / 1.35 grams) * 100% = 85 %

The mass percentage yield is 85%

You might be interested in

. Determine the standard free energy change, ɔ(G p for the formation of S2−(aq) given that the ɔ(G p for Ag+(aq) and Ag2S(s) are

olga nikolaevna [1]

Answer: The standard free energy change of formation of $S^{2-}(aq.)$ is 92.094 kJ/mol

Explanation:

We are given:

$K_{sp}\text{ of }Ag_2S=8\times 10^{-51}$

Relation between standard Gibbs free energy and equilibrium constant follows:

$\Delta G^o=-RT\ln K$

where,

$\Delta G^o$ = standard Gibbs free energy = ?

R = Gas constant = $8.314J/K mol$

T = temperature = $25^oC=[273+25]K=298K$

K = equilibrium constant or solubility product = $8\times 10^{-51}$

Putting values in above equation, we get:

$\Delta G^o=-(8.314J/K.mol)\times 298K\times \ln (8\times 10^{-51})\\\\\Delta G^o=285793.9J/mol=285.794kJ$

For the given chemical equation:

$Ag_2S(s)\rightleftharpoons 2Ag^+(aq.)+S^{2-}(aq.)$

The equation used to calculate Gibbs free change is of a reaction is:

$\Delta G^o_{rxn}=\sum [n\times \Delta G^o_f_{(product)}]-\sum [n\times \Delta G^o_f_{(reactant)}]$

The equation for the Gibbs free energy change of the above reaction is:

$\Delta G^o_{rxn}=[(2\times \Delta G^o_f_{(Ag^+(aq.))})+(1\times \Delta G^o_f_{(S^{2-}(aq.))})]-[(1\times \Delta G^o_f_{(Ag_2S(s))})]$

We are given:

$\Delta G^o_f_{(Ag_2S(s))}=-39.5kJ/mol\\\Delta G^o_f_{(Ag^+(aq.))}=77.1kJ/mol\\\Delta G^o=285.794kJ$

Putting values in above equation, we get:

$285.794=[(2\times 77.1)+(1\times \Delta G^o_f_{(S^{2-}(aq.))})]-[(1\times (-39.5))]\\\\\Delta G^o_f_{(S^{2-}(aq.))=92.094J/mol$

Hence, the standard free energy change of formation of $S^{2-}(aq.)$ is 92.094 kJ/mol

8 0

3 years ago

What is a synthetic reaction?

zubka84 [21]

Synthesis reactions are reactions that occur when two different atoms or molecules interact to form a different molecule or compound. Most of the time, when a synthesis reaction occurs, energy is released and the reaction is exothermic

4 0

3 years ago

Read 2 more answers

How does the air temperature at the bottom of a mountain compare with the air temperature at the top of the mountain?

tia_tia [17]

Explanation: C) the air temp. at the top is lower

5 0

3 years ago

Which of the following planets has ammonia clouds in its atmosphere?

AlekseyPX

Answer:

Jupiter and Saturn has ammonia clouds in its atmosphere since the molecules of ammonia gas that are present in their atmospheres condense to form clouds. However, these ammonia clouds are more visible in Jupiter than in Saturn because of their lower altitude in Saturn.

6 0

3 years ago

How many significants are in 54.0047

erik [133]

Answer:

There are 6

Explanation:

The significant figures in that number are 5 4 0 0 4 7

Hope this helps:)

6 0

3 years ago