Calcium carbonate, CaCO3(s), decomposes upon heating to give CaO(s) and
CO2(g). A sample of CaCO3 is decomposed, and carbon dioxide is collected
in a 250 mL flask. After decomposition is complete, the gas has a pressure
of 1.3 atm at a temperature of 31℃. How many moles of CO2 gas were
generated?
gctc
To find the number of moles of CO2 gas generated, we can use the ideal gas law equation:
PV = nRT
Where:
P = pressure (in atm)
V = volume (in liters)
n = number of moles
R = ideal gas constant (0.0821 L.atm/mol.K for this question)
T = temperature (in Kelvin)
First, we need to convert the temperature from Celsius to Kelvin:
T(K) = T(°C) + 273.15
T(K) = 31 + 273.15
T(K) = 304.15 K
Next, we convert the volume from mL to liters:
V(L) = V(mL) / 1000
V(L) = 250 mL / 1000
V(L) = 0.25 L
Now, we can plug in the values into the ideal gas law equation:
1.3 atm * 0.25 L = n * 0.0821 L.atm/mol.K * 304.15 K
Simplifying the equation:
0.325 L.atm = n * 24.998 L.atm/mol
Dividing both sides by 24.998 L.atm/mol:
n = 0.325 L.atm / 24.998 L.atm/mol
n ≈ 0.013 moles
Therefore, approximately 0.013 moles of CO2 gas were generated.