1 gram of C3H8 gas and 1 gram of O2 gas are delivered to a metal sphere with a fixed volume of 1 L. After the two gases are introduced, the two reactants are ignited and burned according to the balanced reaction

C3H8(g)+5O2(g)changes to3CO2(g)+4H2O(g)
After reaction, the sphere is held at 226.25 oC. What is the final pressure in the sphere given that all the compounds inside are gases and the limiting reagent is completely consumed with 100% yield ?

First determine which is the limiting reagent.

moles C3H8 = 1g/molar mass = about 0.02 but you need to do it more accurately.
moles O2 = 1g/molar mass = about 0.02.

Now convert moles C3H8 to moles CO2. I have about 0.06.
Convert moles O2 to moles CO2. I have about 0.02.
Both answers can't be correct; the correct value in limiting reagent problems is ALWAYS the smaller value and the reagent providing that value is the limiting reagent. Therefore, O2 is the limiting reagent.
Since all of that will be consumed, you should convert moles O2 to moles C3H8 to determine moles C3H8 consumed, then subtract from initial moles to determine how much C3H8 remains unreacted. Add moles C3H8 + moles CO2 + moles H2O and use PV = nRT to solve for final P.

To find the final pressure in the sphere, we need to use the ideal gas law equation:

PV = nRT

Where:
P = pressure of the gas
V = volume of the gas (1 L in this case)
n = number of moles of gas
R = ideal gas constant (0.0821 L·atm/mol·K)
T = temperature of the gas in Kelvin

First, let's find the number of moles of each reactant.

The molar mass of C3H8 (propane) is 44 g/mol. Therefore, 1 gram of C3H8 is equal to 1/44 = 0.0227 moles.

The molar mass of O2 is 32 g/mol. Therefore, 1 gram of O2 is equal to 1/32 = 0.03125 moles.

From the balanced equation, we can see that the reaction needs one mole of C3H8 and five moles of O2 to react completely. However, since O2 is the limiting reagent, only 0.03125 moles of O2 will react, and 0.0227 moles of C3H8 will react as well.

Now, let's calculate the number of moles of each product formed.

Since the balanced equation shows that three moles of CO2 and four moles of H2O are formed from one mole of C3H8, we can multiply the number of moles of C3H8 by the stoichiometric coefficients:

CO2: 0.0227 moles of C3H8 * 3 moles CO2 / 1 mole C3H8 = 0.0681 moles of CO2
H2O: 0.0227 moles of C3H8 * 4 moles H2O / 1 mole C3H8 = 0.0908 moles of H2O

Therefore, after the reaction, we will have 0.0681 moles of CO2 and 0.0908 moles of H2O in the sphere.

Now, let's convert the temperature to Kelvin. Given that the temperature is 226.25 oC, we add 273.15 to get:

T = 226.25 + 273.15 = 499.40 K

Now we are ready to use the ideal gas law equation:

P * 1 = (0.0681 + 0.0908) * 0.0821 * 499.40

Simplifying this equation:

P = (0.1589) * (40.972)

P = 6.507 atm

Therefore, the final pressure in the sphere is approximately 6.507 atm.