suppose you need 2.0L of 6.0mol sulfuric acid and you have a bottle of concentrated acid of 18.0mol sulfuric acid. (a) How much of this would be need to a 2L of 6.0mol sulfuric acid solution? (b)Describe how you would prepare this solution?
you are reducing the molarity by a factor of 3, so you need to increase the volume by a factor of 3.
1/3 acid and 2/3 water
don't add the acid to the water!
To solve this problem, you need to use the concept of dilution. Dilution is the process of reducing the concentration of a solute in a solution by adding more solvent. In this case, you have concentrated sulfuric acid (18.0 mol/L) and you need to prepare a 6.0 mol/L solution.
(a) To find out how much concentrated acid you need, you can use the formula for dilution:
C1V1 = C2V2
Where:
C1 = concentration of the concentrated acid
V1 = volume of the concentrated acid
C2 = concentration of the resulting solution
V2 = total volume of the resulting solution
In this case, you have:
C1 = 18.0 mol/L
C2 = 6.0 mol/L
V2 = 2.0 L (total volume of the resulting solution, which is given)
Rearranging the formula, we can solve for V1:
V1 = (C2V2) / C1
Substituting the values, we have:
V1 = (6.0 mol/L * 2.0 L) / 18.0 mol/L
Simplifying the equation, we find:
V1 = 0.6667 L or approximately 0.67 L
Therefore, you would need approximately 0.67 L of the concentrated sulfuric acid to prepare a 2.0 L solution of 6.0 mol/L sulfuric acid.
(b) To prepare the 6.0 mol/L sulfuric acid solution, you would follow these steps:
1. Measure out approximately 0.67 L of the concentrated sulfuric acid, ensuring proper safety precautions (such as wearing gloves and eye protection) since concentrated acids are corrosive and can be harmful.
2. Add this measured amount of concentrated acid to a suitable container, such as a beaker.
3. Slowly and carefully add distilled water to the container while stirring gently. The amount of water required can be calculated by subtracting the volume of the concentrated acid from the final desired volume of the solution.
- In this case, since you need a final volume of 2.0 L, you would add approximately 1.33 L (2.0 L - 0.67 L) of distilled water.
4. Continue stirring until the concentrated acid and water have mixed thoroughly.
5. Once the solution is well mixed, you have prepared a 2.0 L solution of 6.0 mol/L sulfuric acid.
Note: It is crucial to remember that when diluting concentrated acids, always add acid to water slowly, never the other way around. This helps prevent rapid heat generation and potential splashing.