Oxygen gas can be generated by heating KClO3 in the presence of some MnO2.
2KClO3 → 2KCl + 3O2
If all the KClO3 in a mixture containing 1.58 g KClO3 and 0.30 g MnO2 is decomposed, how many liters of O2 gas will be generated at T = 25.0°C and P = 760.6 torr?
I assume that ONLY the KClO3 is decomposing.
mols KClO3 = 1.58/molar mass KClO3.
Using the coefficients in the balanced equation, convert mols KClO3 to mols O2.
Now use PV = nRT, substitute n for mols and the other conditions of the problem and solve for V in liters. Remember T mut be in kelvin and P in atmospheres is R = 0.08206 L*atm/mol*K
To find the number of liters of O2 gas generated, we need to use the ideal gas law equation: PV = nRT, where P is the pressure (in atm), V is the volume (in liters), n is the number of moles, R is the ideal gas constant (0.0821 L.atm/mol.K), and T is the temperature (in Kelvin).
First, we need to calculate the number of moles of O2 gas generated. We can do this by using the stoichiometry of the balanced chemical equation:
2KClO3 → 2KCl + 3O2
From the balanced equation, we can see that for every 2 moles of KClO3 decomposed, 3 moles of O2 gas are produced. Therefore, we need to find the number of moles of KClO3 and then convert it to moles of O2 gas.
1. Calculate the number of moles of KClO3:
moles of KClO3 = mass of KClO3 / molar mass of KClO3
The molar mass of KClO3 can be calculated by adding up the atomic masses of each element in the compound:
molar mass of KClO3 = (molar mass of K) + (molar mass of Cl) + 3*(molar mass of O)
The atomic masses for K, Cl, and O are 39.1 g/mol, 35.45 g/mol, and 16.00 g/mol, respectively.
2. Calculate the number of moles of O2:
moles of O2 = (moles of KClO3) * (3 moles of O2 / 2 moles of KClO3)
Now that we have the number of moles of O2, we can calculate the volume of O2 gas using the ideal gas law equation:
3. Convert the temperature from Celsius to Kelvin:
T(K) = T(°C) + 273.15
4. Calculate the volume of O2 gas:
V = (nRT) / P
Substituting the values:
V = (moles of O2) * (R) * (T(K)) / P
Make sure to convert the pressure from torr to atm:
P(atm) = P(torr) / 760
By plugging in the values for moles of O2, R, T(K), and P(atm), you can calculate the volume (V) of O2 gas generated in liters.