Antacid tab is dissolved in water and a few drops of phenolphthalein is added yielding bright pink solution. 0.2025 M HCl added until pink color disappears. The 0.2147 M NaOH added until it turns light pink for ~30 seconds.
mass on antacid tablet = 1.056g
initial V 0.2025 M HCl = 1.97 mL
final V of 0.2025 M HCl = 42.26 mL
initial V of 0.2137 M NaOH = 0.89 mL
final V 0.2147 M NaOH = 17.32 mL
How many millimoles of acid are neutralized per antacid tablet and per gram of antacid tablet?
So I have 40.29 mL HCL used and
16.43 mL NaOH used.
I don't know where to go from there.
millimols HCl initially = M x mL = ? = mmols to more than neutralize the antacid.
mmols NaOH added to neutralize the excess HCl = M x mL = ?
mmols HCl - mmol NaOH = mmols HCl used to neutralize the anacid tab. That answers the first question.
The second is mmols HCl/1.056g = ? which gives the second answer.
To find the millimoles of acid neutralized per antacid tablet and per gram of antacid tablet, you need to calculate the number of millimoles of acid neutralized by the HCl and NaOH solutions.
First, let's calculate the number of millimoles of acid neutralized by the HCl solution:
1. Calculate the volume of HCl used: final volume - initial volume = 42.26 mL - 1.97 mL = 40.29 mL.
2. Convert the volume of HCl used to liters: 40.29 mL * (1 L / 1000 mL) = 0.04029 L.
3. Calculate the number of millimoles of HCl used using the molarity (0.2025 M) and volume: 0.04029 L * 0.2025 mol/L = 0.008175225 mol.
4. Convert the number of moles to millimoles: 0.008175225 mol * (1000 mmol/1 mol) = 8.175225 mmol.
Next, let's calculate the number of millimoles of acid neutralized by the NaOH solution:
1. Calculate the volume of NaOH used: final volume - initial volume = 17.32 mL - 0.89 mL = 16.43 mL.
2. Convert the volume of NaOH used to liters: 16.43 mL * (1 L / 1000 mL) = 0.01643 L.
3. Calculate the number of millimoles of NaOH used using the molarity (0.2147 M) and volume: 0.01643 L * 0.2147 mol/L = 0.003527641 mol.
4. Convert the number of moles to millimoles: 0.003527641 mol * (1000 mmol/1 mol) = 3.527641 mmol.
Now, to find the millimoles of acid neutralized per antacid tablet, divide the millimoles of acid neutralized by each solution by the number of tablets used (assuming one tablet was used):
Millimoles of HCl neutralized per tablet = 8.175225 mmol / 1 = 8.175225 mmol
Millimoles of NaOH neutralized per tablet = 3.527641 mmol / 1 = 3.527641 mmol
Lastly, to find the millimoles of acid neutralized per gram of antacid tablet, divide the millimoles of acid neutralized per tablet by the mass of the tablet:
Millimoles of HCl neutralized per gram = 8.175225 mmol / 1.056 g = 7.743066 mmol/g
Millimoles of NaOH neutralized per gram = 3.527641 mmol / 1.056 g = 3.339623 mmol/g
Therefore, approximately 8.18 millimoles of acid are neutralized per antacid tablet, and approximately 7.74 millimoles of HCl and 3.34 millimoles of NaOH are neutralized per gram of antacid tablet.