Determine the mass of CaCO3 in your TUMS tablet?
The weight of the tablet was 0.013g
Concentration of HCl was 0.1494 M
Volume of HCl was 95 mL
Concentration of NaOH was 0.1422 M
The average amount it took to titrate was 2.13 mL
I have determined that moles of HCl neutralized was 0.014039514 and when I divide by 2 and multiply by the molar mass of CaCO3 I get 0.702607478 which is way more than the weight of my TUMS
I can't figure out what I did wrong
You may want to double check the weight of your tablet as your current one is extremely light.
To determine the mass of CaCO3 in your TUMS tablet, you need to use the stoichiometry of the reaction between HCl and CaCO3.
First, let's calculate the moles of HCl used in the titration:
Moles of HCl = concentration of HCl x volume of HCl
Moles of HCl = 0.1494 M x 95 mL
Moles of HCl = 0.014229 mol
Since it took 2.13 mL of HCl to neutralize the solution, we need to divide the moles of HCl by 2.13 mL:
Moles of HCl neutralized = 0.014229 mol / (2.13 mL / 1000)
Moles of HCl neutralized = 0.014229 mol / 0.00213 L
Moles of HCl neutralized = 6.6789 mol/L
Now, we can use the stoichiometry of the reaction between HCl and CaCO3 to determine the moles of CaCO3:
1 mole of CaCO3 reacts with 2 moles of HCl
Moles of CaCO3 = (moles of HCl neutralized) x (1 mole of CaCO3 / 2 moles of HCl)
Moles of CaCO3 = 6.6789 mol/L x (1/2)
Moles of CaCO3 = 3.3394 mol/L
Finally, to determine the mass of the CaCO3 in your TUMS tablet, you can use the formula:
Mass of CaCO3 = moles of CaCO3 x molar mass of CaCO3
The molar mass of CaCO3 is:
Ca: 40.08 g/mol
C: 12.01 g/mol
O (3 atoms): 16.00 g/mol
Molar mass of CaCO3 = 40.08 g/mol + 12.01 g/mol + (3 x 16.00 g/mol)
Molar mass of CaCO3 = 100.09 g/mol
Now, let's calculate the mass of the CaCO3:
Mass of CaCO3 = 3.3394 mol x 100.09 g/mol
Mass of CaCO3 = 334.4 g
Based on your calculations, it seems that you divided by 2 when you shouldn't have. The correct calculation for determining the moles of CaCO3 is to multiply the moles of HCl neutralized by the stoichiometric ratio of CaCO3 to HCl, which is 1:2.
To determine the mass of CaCO3 in your TUMS tablet, you need to perform a back-titration using HCl and NaOH. It seems that you have already calculated the moles of HCl neutralized during the titration (0.014039514 mol).
Let's go over the steps again to identify where the mistake might have occurred:
1. Convert the volume of NaOH used for back-titration from mL to L:
Volume of NaOH (V_naoh) = 2.13 mL = 0.00213 L
2. Calculate the moles of NaOH used in the titration by using the equation:
moles of NaOH = (concentration of NaOH) x (volume of NaOH)
moles of NaOH = 0.1422 M x 0.00213 L
3. Determine the moles of excess HCl remaining after reaction with NaOH:
moles of HCl remaining after reaction = moles of NaOH used - moles of HCl neutralized
moles of HCl remaining after reaction = (moles of NaOH) - 0.014039514 mol
4. Determine the moles of CaCO3 in your TUMS tablet. Since the balanced equation between HCl and CaCO3 is 2HCl + CaCO3 -> CaCl2 + H2O + CO2, you know that 2 moles of HCl neutralize 1 mole of CaCO3.
moles of CaCO3 = (moles of HCl remaining after reaction) / 2
5. Calculate the mass of CaCO3 using the equation:
mass of CaCO3 = (moles of CaCO3) x (molar mass of CaCO3)
Check your calculations again to see if any errors were made. Remember to use accurate values for the concentrations, volumes, and molar masses.