1. Which is the strongest antacid, on a single-dose basis? Which is the weakest? Explain and show your calculations.

The strongest antacid, on a single-dose basis is the CVS brand antacid. This is because the CVS brand volume of NaOH is .000995 mL which is the lease amount needed to neutralize the remaining acid meaning it is the strongest antacid. The weakest antacid is Rennies antacid, on a single-dose basis because it requires .00122 mL of NaOH to neutralize the remaining acid which is the highest amount needed.

Work:

Maalox- moles of NaOH = 0.05mol/l x 24.1mL = 1.205 mmol/1000 = .001205 mol

Tums- moles of NaOH = 0.05mol/l x 22.4mL = 1.120 mmol/1000 = .00112 mol

Mylanta- moles of NaOH = 0.05mol/l x 20.0mL = 1.00 mmol/1000 = .001 mol

CVS Brand- moles of NaOH = 0.05mol/l x 19.9mL = 0.995 mmol/1000 = .000995 mol

Rennies- moles of NaOH = 0.05mol/l x 24.4mL = 1.220 mmol/1000 = .00122 mol

2. Which are the strongest and weakest, on a by-weight (mass) basis?

The strongest antacid, on a by-weight basis is Tums while Rennies is the weakest antacid, on a by-weight basis. This was determined by the amount of acid 1g of the antacids would be able to neutralize in a single dose.

Work:

Maalox = 24.1ml/20.0g = 1.21ml/g

.002795 mol base / 20.0g = .00013975 mol base/pill Maalox

Tums = 22.4ml/21.0g = 1.07ml/g

.002880 mol base / 21.0g = .0001371 mol base/pill Tums

Mylanta = 20.0ml/18.0g = 1.11ml/g

.003 mol base / 18.0g = .0001666 mol base/pill Mylanta

CVS Brand = 19.9ml/18.3g = 1.09ml/g

.003005 mol base / 18.3g = .0001642 mol base/pill CVS brand

Rennies = 24.4ml/ 17.5g = 1.39ml/g

.002780 mol base / 17.5g = .0001588 mol base/pill Rennies

3. When people do back titrations, they usually watch the solution for a color change when the solution becomes neutral. What might you have used in the above experiment to get this color change to happen in the solution? At what pH would the solution have been neutral?

The solution for a color...