Question

calculations for the % CaO using these numbers from

the experiment are not right. I need help figuring out how to calculate the percentage

1 Trial 2 l rial Trial 3 Hal (rapp Mass of CaCO mL H20 100.00 standard (g)0.1434 Volume of CaCO3 used (mL) Volume of EDTA used (mL) as.elmLIAk,7| n,し1a8.48mL 3 Conc. EDTA (M) Average Conc. EDTA (M) %Relative Standard Deviation (RSD) Mass of unknown Ca2" (g) Volume of unknown 3 | 9 , 31 100.00 mL H20 used omayion 100 ml 10.00 L 10.10 mL Volume of EDTA used (mL) % CaO for Unknown % CaO Average for Unknown Standard Deviation %Relative Standard Deviation 95% Cl

Answer 1

First, the added moles of EDTA are calculated:

n EDTA = M * V = 2.19x10 ^ -3 M * 0.03127 L = 6.85x10 ^ -5 mol

Trial 2: 6.75x10 ^ -5 mol

Trial 3: 6.77x10 ^ -5 mol

The moles of EDTA are the same moles of CaO, with the molar weight the grams CaO are calculated:

g CaO = n * MM = 6.85x10 ^ -5 mol * (56.08 g / 1 mol) = 0.0038 g

Trial 2: 0.0038 g

Trial 3: 0.0038 g

The percentage of CaO is calculated, taking into account that the diluted volume is 1/10, the sample grams are divided into 10 and it is calculated:

% CaO = g CaO * 100 / g sample / 10 = 0.0038 * 100 / 0.01493 g = 25.45%

Trial 2: 25.45%

Trial 3: 25.45%

Standard deviation = 0%

Relative = 0

If you like the answer, please rate it in a positive way, you will help me a lot, thank you.