Please help ASAP. C3H8 + 5O2 ---> 4H2O + 3CO2 1. How many moles of oxygen gas are needed to react with excess propane (C3H8) in order to form 5.32 moles of water?
2. What mass of carbon dioxide is produced from 13 grams of oxygen gas and excess propane?
3. What mass of propane is needed in order to produce 2.70 moles of water?

c, liquids evaporate, creating a gas

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol