Question

the average edta concentration after being standardized was calculated to be 0.02018 m and you used 13.56 ml to reach the endpoint with 25ml of your unknown. what is the ppm of caco3 in the unknown? (formula wt of caco3

Answer 1

To calculate the ppm of CaCO3, first determine the moles of EDTA used in titration, convert these to moles of CaCO3, then to mass, and finally to ppm relative to the sample volume. We have 1095600 ppm.

Step-by-step explanation:

To calculate the ppm of CaCO3 in the unknown, we will use the known concentration of EDTA and the volume of EDTA used in the titration. The molecular weight of CaCO3 (calcium carbonate) is 100.087 g/mol.

Firstly, we can calculate the moles of EDTA used in the titration:

• Moles of EDTA = Concentration of EDTA × Volume of EDTA (in liters)
  
• Moles of EDTA = (0.02018 M) × (0.01356 L)
• Moles of EDTA = 0.00027364 mol

Since the reaction between EDTA and CaCO3 is in a 1:1 molar ratio, the moles of CaCO3 will also be 0.00027364 mol.

We then convert the moles of CaCO3 to grams:

• Mass of CaCO3 = Moles of CaCO3 × Molecular weight of CaCO3
• Mass of CaCO3 = 0.00027364 mol × 100.087 g/mol
• Mass of CaCO3 = 0.02739 g

Now we calculate the ppm (parts per million) concentration:

• ppm of CaCO3 = (Mass of CaCO3 in grams / Volume of solution in liters) × 1,000,000
• ppm of CaCO3 = (0.02739 g / 0.025 L) × 1,000,000
• ppm of CaCO3 = 1095600 ppm