05 mL of sample water needs10.9 mL .01M EDTA solution. what is the accurate Hardness of sample in CaCO3 (mg/L)? pls expalin.
EDTA complexes CaCO3.
Here is explanation.
http://www.austincc.edu/dsackett/CHEM1412/lab/1412exp47.pdf
To find the accurate hardness of the sample water in CaCO3 (mg/L), you need to perform a titration using the given sample water and the .01M EDTA solution.
Here's a step-by-step explanation of the process:
1. Convert the given volume of the sample water from mL to liters:
- 05 mL = 0.05 L
2. Determine the moles of EDTA solution used in the titration:
- Since the concentration of the EDTA solution is 0.01M and the volume used is 10.9 mL, convert the volume to liters:
- 10.9 mL = 0.0109 L
- Use the formula: moles = concentration × volume (in liters)
- Moles of EDTA = 0.01M × 0.0109 L
3. Assign stoichiometric coefficients to find the moles of CaCO3:
- The balanced chemical equation between EDTA and CaCO3 is:
CaCO3 + H2EDTA → Ca(EDTA) + CO2 + H2O
- The stoichiometric coefficient of CaCO3 is 1.
4. Calculate the moles of CaCO3:
- Since the stoichiometric coefficient of CaCO3 is 1, the moles of CaCO3 will be equal to the moles of EDTA.
5. Calculate the molar mass of CaCO3:
- The molar mass of CaCO3 is the sum of the atomic masses of calcium (Ca), carbon (C), and three oxygen (O) atoms.
6. Calculate the mass of CaCO3:
- Use the formula: mass = moles × molar mass
7. Convert the mass of CaCO3 to milligrams (mg):
- 1 g = 1000 mg
8. Calculate the hardness of the sample in CaCO3 (mg/L):
- Use the formula: hardness = (mass of CaCO3 in mg) / volume of sample water (in L)
By following these steps and performing the necessary calculations, you will be able to determine the accurate hardness of the sample water in CaCO3 (mg/L).