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3 years ago

How much sodium chloride (NaCl) would need to be added to 750 milliliters of water to make a 15% solution?

Chemistry

1 answer:

oee [108]3 years ago

5 0

Answer: 6.58g

Explanation: We are to find the mass of NaCl that can produce 15% solution in a 750ml

STEP 1:

the reaction moles

NaCl + H2O = NaOH + HCl

Therefore 1mole of NaCl reacts with 1mole of H2O

STEP 2:

convert 750ml to liter

750ml × 1L/1000ml = 0.750L

STEP3 :

convert percentage concentration to mol/L

15% = 0.15mol/L

STEP 4:

find the mole

Mole= concentration× volume

0.15mol/L × 0.75L =0.1125mol

STEP 5 :

Find the mass

Mass = mole × molar mass

The molecular mass of NaCl is 23+35.5= 58.5g/mol

Therefore:

0.1125mol × 58.5g/mol = 6.58g

Approximately: 6.6g

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3 years ago

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3 years ago

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)

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

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

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$C_7H_6O_3+C_4H_6O_3\rightarrow C_9H_8O_4+CH_3COOH$

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:

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

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Putting values in above equation, we get:

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

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3 years ago

40 g of CaCO3 is how many moles of CaCO3? 10 moles 0.4 moles 40 moles 100 moles

AleksandrR [38]

Answer:

0.4 moles

Explanation:

To convert between moles and grams you need the molar mass of the compound. The molar mass of of CaCO3 is 100.09g/mol. You use that as the unit converter.

40gCaCO3* 1mol CaCO3/100.09gCaCO3 = 0.399640 mol CaCO3

This rounds to 0.4 moles CaCO3

8 0

3 years ago