13. a concentrated sulfuric acid solution is available in a lab. a 100 - ml solution with a concentration of…

13. a concentrated sulfuric acid solution is available in a lab. a 100 - ml solution with a concentration of 0.75 mol/l is required. write out the pre - lab and procedure for making this solution.

13. a concentrated sulfuric acid solution is available in a lab. a 100 - ml solution with a concentration of 0.75 mol/l is required. write out the pre - lab and procedure for making this solution.

Answer

Brief Explanations:

Pre - lab involves gathering materials (concentrated sulfuric acid, distilled water, volumetric flask, pipette, safety equipment like goggles and gloves), calculating the volume of concentrated acid needed using the dilution formula $C_1V_1 = C_2V_2$. The procedure is to first measure the required volume of concentrated acid carefully using a pipette, transfer it to a volumetric flask partially filled with distilled water, swirl gently, then add more distilled water to the mark on the volumetric flask and mix well.

Answer:

Pre - lab:

  1. Gather materials: Concentrated sulfuric acid, distilled water, 100 - mL volumetric flask, pipette, safety goggles, gloves.
  2. Calculate volume of concentrated acid: Let the concentration of concentrated sulfuric acid be $C_1$ (unknown, but known for the stock solution), the volume of concentrated acid be $V_1$, the final concentration $C_2=0.75\ mol/L$ and final volume $V_2 = 100\ mL=0.1\ L$. Using $C_1V_1 = C_2V_2$, solve for $V_1=\frac{C_2V_2}{C_1}$.

Procedure:

  1. Put on safety goggles and gloves.
  2. Measure the calculated volume of concentrated sulfuric acid using a pipette.
  3. Transfer the measured acid into a 100 - mL volumetric flask that is partially filled with distilled water.
  4. Swirl the flask gently.
  5. Add distilled water to the volumetric flask up to the 100 - mL mark.
  6. Mix the solution thoroughly by inverting the flask several times.