Pls ease do number 1 and 2 Preparation and standardization of Reagents Prepare 5
ID: 531761 • Letter: P
Question
Pls ease do number 1 and 2 Preparation and standardization of Reagents Prepare 500ml of 0.010M sodium carbonate using solid Na_2CO_3 and water (in a 500mL volumetric flask). The Na_2CO_3 has been dried in a drying oven. Try to keep reagent bottle closed as much as possible. Exposure to air will throw off the reagents weight. You will be provided with a stock solution of sulfuric acid that is approximately 0.1M. Prepare 500.0 ml of ~0.0025M H_2SO_4 by diluting the stock solution (in a 500mL volumetric flask), (reminder you always add acid to water and not the other way.) You will determine the exact concentration of the solution in Step 6. Fill a buret with 0.010M Na_2CO_3 from step 1. Check to be sure that there are no air bubbles in the tip of the buret. Record the initial volume of Na_2CO_3 to two decimal places. Using a pipet or a buret, carefully add 50.00 mL of 0.0025M H_2SO_4 to a 250mL Erlenmeyer flask. Add 2 or 3 drops of phenolphthalein indicator. Slowly add 0.010M Na_2CO_3 to the mixture in the Erlenmeyer flask until the color of the solution changes from colorless to pink. Record the final volume in your buret to two decimal places. Repeat steps 3-5 to check for reproducibility. Since all your subsequent calculations depend on these standardization steps, it is important that your data are as accurate and precise as possible.Explanation / Answer
Q1.
V = 500 mL required
M = 0.01 M of Na2CO3
mol = MV = (500*0.01) = 5 mmol of Na2CO3 required
so
mass of Na2CO3 = mmol*MW = 5*105.9888 = 529.944 mg of Na2CO3 = 0.529944 g of Na2CO3
now...
add 0.529944 g to the flask/beaker, then add water until V = 500 mL
Stirr and you will have your solution of 0.01 M Na2CO3 with V = 500 mL