An antacid tablet weighing 1.462 grams was dissolbed in 25mL of 0.8M HCl and diluted with water. The excess HCl was titrated with 3.5 mL of 1.019M NaOH solution.
1. Calculate the number of millimoles added to the tablet
2. Calculate the number of millimoles of NaOH required to neutralize the excess HCl left over
3. Calculate the number of millimoles of HCl that neutralized the tablet.
1) mmoles HCl added to tablet = mL x M = ??
2) mmoles NaOH added to HCl = mL x M = ??
3) #1-#2=#3
To calculate the number of millimoles added to the tablet, you need to find the number of moles of HCl that reacted with the antacid tablet.
Step 1: Calculate the number of moles of HCl that reacted with the antacid tablet.
First, convert the weight of the antacid tablet to moles using its molar mass. The molar mass of the antacid tablet is the total combined molar masses of all the elements in the tablet.
For example, if the antacid tablet contains calcium carbonate (CaCO3), the molar mass is:
(40.08 g/mol for calcium) + (12.01 g/mol for carbon) + (3 x 16.00 g/mol for oxygen) = 100.09 g/mol
So, if the antacid tablet weighs 1.462 grams, the number of moles of the antacid tablet is:
1.462 g / 100.09 g/mol = 0.01461 moles
Step 2: Calculate the number of moles of HCl that reacted with the antacid tablet.
Use the balanced equation between HCl and the antacid to determine the mole ratio. For example, if the balanced equation is:
CaCO3 + 2HCl → CaCl2 + H2O + CO2
You can see that 1 mole of calcium carbonate reacts with 2 moles of HCl. So, the number of moles of HCl that reacted with the antacid tablet is:
0.01461 moles x 2 = 0.02922 moles
Step 3: Convert the number of moles of HCl to millimoles.
Since you need to calculate the number of millimoles added, multiply the number of moles of HCl by 1000 to convert to millimoles.
0.02922 moles x 1000 = 29.22 millimoles
Therefore, the number of millimoles added to the tablet is 29.22 millimoles.
To calculate the number of millimoles of NaOH required to neutralize the excess HCl left over, you can use the balanced equation between NaOH and HCl.
For example, if the balanced equation is:
NaOH + HCl → NaCl + H2O
You can see that 1 mole of NaOH reacts with 1 mole of HCl. So, the number of moles of NaOH required is equal to the number of moles of HCl used to neutralize the excess HCl.
To find the number of moles of NaOH, use the concentration of NaOH and the volume used in the titration:
Step 1: Calculate the number of moles of NaOH used in the titration.
The concentration of NaOH is given as 1.019 M.
The volume of NaOH used is 3.5 mL, which can be converted to liters by dividing by 1000:
3.5 mL / 1000 = 0.0035 L.
Using the formula Molarity = Moles/Liters, you can calculate the number of moles of NaOH:
1.019 M = Moles/0.0035 L
Rearranging the equation to solve for Moles, we get:
Moles = 1.019 M x 0.0035 L = 0.0035665 moles
Step 2: Convert the number of moles of NaOH to millimoles.
Since you need to calculate the number of millimoles, multiply the number of moles by 1000 to convert to millimoles.
0.0035665 moles x 1000 = 3.5665 millimoles
Therefore, the number of millimoles of NaOH required to neutralize the excess HCl left over is 3.5665 millimoles.
To calculate the number of millimoles of HCl that neutralized the tablet, you can use the balanced equation between HCl and the antacid.
For example, if the balanced equation is:
CaCO3 + HCl → CaCl2 + H2O + CO2
You can see that 1 mole of HCl reacts with 1 mole of calcium carbonate. So, the number of moles of HCl that neutralized the tablet is equal to the number of moles of calcium carbonate in the tablet.
From Step 1 in the first calculation, the number of moles of the antacid tablet is 0.01461 moles.
Convert the number of moles of HCl to millimoles:
0.01461 moles x 1000 = 14.61 millimoles
Therefore, the number of millimoles of HCl that neutralized the tablet is 14.61 millimoles.