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3 years ago

The density of a 20.3 M CH 3OH (methanol) solution is 0.858 g/mL.

Chemistry

1 answer:

RUDIKE [14]3 years ago

4 0

Answer:

Molality is 97.6 m (option e)

Explanation:

Density relates mass/volume. It is a data which is involved always to solutions, not solute, neither solvent.

0.858 g/mL = solution mass / 1000mL

0.858 g/mL .1000 mL = 858 grams of solution

Mole of solute = 20.3

Molar weight methanol = 32.04 g/m

Mass of methanol, in solution = molar weight . mol

32.04 g/m . 20.3 = 650.4 g

Mass of solution = Mass of solvent + Mass of solute

858 g = Mass of solvent + 650.4g

Mass of solvent = 858 g - 650.4 g → 207.6 g

So 20.3 moles of solute are contained in 207.6 g of solvent.

Molality is moles of solute/kg of solvent

20.3 m / 0.2076 kg = 97.6 m

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Aspirin sun thesis Green Chemistry and Assime the aspirin is prepared by the following reaction and that 10.09. of salicylic aci

klemol [59]

Answer: The percentage yield of aspirin is 38.02 %.

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For salicylic acid:

Given mass of salicylic acid $(C_7H_6O_3)$ = 10.09 g

Molar mass of salicylic acid $(C_7H_6O_3)$ = 138.12 g/mol

Putting values in equation 1, we get:

$\text{Moles of salicylic acid}=\frac{10.09g}{138.12g/mol}=0.0730mol$

The chemical equation for the formation of aspirin follows:

$C_7H_6O_3+C_4H_6O_3\rightarrow C_9H_8O_4+CH_3COOH$

As, acetic anhydride is present in excess. So, it is considered as an excess reagent.

Thus, salicylic acid is a limiting reagent because it limits the formation of products.

By Stoichiometry of the reaction:

1 mole of salicylic acid produces 1 mole of aspirin.

So, 0.0730 moles of salicylic acid will produce = $\frac{1}{1}\times 0.0730=0.0730mol$ of aspirin

Now, calculating the mass of aspirin from equation 1, we get:

Molar mass of aspirin = 180.16 g/mol

Moles of aspirin = 0.073 moles

Putting values in equation 1, we get:

$0.073mol=\frac{\text{Mass of aspirin}}{180.16g/mol}\\\\\text{Mass of aspirin}=13.15g$

To calculate the percentage yield of aspirin, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield of aspirin = 5.0 g

Theoretical yield of aspirin = 13.15 g

Putting values in above equation, we get:

$\%\text{ yield of aspirin}=\frac{5.0g}{13.15g}\times 100\\\\\% \text{yield of aspirin}=38.02\%$

Hence, the percent yield of aspirin is 38.01 %.

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3 years ago

Consider the reaction.

N76 [4]

Answer: m = 50 g ZnSO4

Explanation: First is convert the moles of Zn to the moles of ZnSO4 by having their mole ratio which is 2:2 based from the balanced equation. Next is convert the moles of ZnSO4 to mass using its molar mass.

0.311 mole Zn x 2 moles ZnSO4 / 2 moles Zn

= 0.311 moles ZnSO4

0.311 moles ZnSO4 x 161 g ZnSO4 / 1 mole ZnSO4

= 50 ZnSO4

5 0

3 years ago

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Answer:

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Explanation:

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Ksivusya [100]

Answer:

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Explanation:

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3 years ago