Answer for exercises below

Question

If 68.4 grams of carbonic acid are sealed in a 2.00 L soda bottle at room temperature (298 K) and decompose completely via the equation below, what would be the final pressure of carbon dioxide assuming it had the full 2.00 L in which to expand? H₂CO₃(aq) → H₂O(l) + CO₂(g)

Answer 1

The final pressure of the carbon dioxide gas will 13.495atm.

Explanation:

molar mass of carbonic acid = 62 g/mol

Moles of carbonic acid = 68.4g / (62g/mol )= 1.103 mol

As per the given reaction

H₂CO₃(aq) → H₂O(l) + CO₂(g)

According to reaction, 1 mol of carbonic acid gives 1 mole of carbon dioxide gas.

Then 1.103 moles of carbonic acid will give :

1.103 mole of carbon dioxide

Therefore from above data

Moles of carbon dioxide gas = n = 1.103 mol

Volume of soda bottle i.e V given = 2L

Pressure of the carbon dioxide gas = P

Temperature of the carbon dioxide gas = T = 298 K

using ideal gas law i.e PV = nRT

P = nRT/V

P = 1.103 mol x 0.0821 L atm mol^-1K^-1 x 298 K / 2L

P = 13.495 atm

The final pressure of the carbon dioxide gas will 13.495 atm.