Question

When a calcium carbonate tablet, like tums, is ingested, it dissolves by reacting with stomach acid, which contains hydrochloric acid. The equation for this reaction is CaCO3(s) + HCl(aq) --->CaCl2(aq) + H2O (I) + CO2(g). How many ml of carbon dioxide would be formed at 37 degree Celsius and 1 atmosphere if sufficient calcium carbonate was ingested to react with 24.9 grams of stomach acid containing 9.5 % HCl by mass?

Answer 1

Balanced chemical reaction is

CaCO_3(s) + 2HCl CaCl_2(aq) + H₂O_(l) + CO_2(g)

mass of solute = % by mass of solute X mass of solution / 100

mass of HCl is stomach acid = 9.5 X 24.9 / 100 = 2.3655 gm

molar mass of HCl = 36.46 gm/mole then 2.3655 mole of HCl = 2.3655 / 36.46 = 0.06488 mole

According to reaction 2 mole HCl produce 1 mole CO₂ then 0.06488 mole of HCl produce CO₂ = 0.6488 / 2 =

0.03244 mole

0.03244 mole of CO₂ produced

Use ideal gas equation to calculate volume of CO₂ produced

We know that PV = nRT

V = nRT/P

n = 0.03244 mole,

T = 37⁰C = 37 +273.15 = 310.15K,

P= 1 atm,

R = 0.08205 L atm mol^-1 K^-1 ( R = gas constant)

V = ?

Substitute these value in above equation.

V = 0.03244 X 0.08205 X 310.15/1 = 0.8255 L

0.8255 L = 825.5 ml

825.5 ml CO₂ produced