Question

One container of Tums costs 4.00 dollars. Each container has eighty 1.00 g tablets. Assume each Tums is 40.0 percent CaCO3 by mass. Using only Tums, you are required to neutralize 0.500 L of 0.400 M HCl. How much does this cost? Assume you are able to purchase individual tablets. Express your answer in dollars.

Answer 1

The balanced reaction will be---

2 HCl + CaCO₃-------> CaCl₂ + H₂O + CO₂

mol ratio of CaCO₃ and HCl is 1:2

moles of HCl will be as---

0.500 L HCl x 0.4 mol/L = 0.2 mol HCl

moles of CaCO₃ will be as---

0.2 mol HCl x 1 mol CaCO₃ / 2 mol HCl = 0.1 mol CaCO₃

Mass of CaCO₃ can be calculated as---

0.1 mol CaCO₃ x 100.1 g / 1 mol CaCO₃ = 10.01 g CaCO₃

Now, 40.0 % CaCO₃ = 40/100 = 0.4

mass of CaCO₃ / (80 tablets x 1 g/tablet x 0.4) = number of containers.

=> 10.01 / 32 = 0.3128125 (number of containers)

Cost = Number of containers x $4 / container = 0.3128125 x $ 4 = $ 1.25