Use the following chemical equation to answer the question. 4K(s) + O2(g) → 2 K2O(s)

If a staff member at a laboratory has 12.0 grams of potassium metal, what mass of potassium oxide could the scientist potentially produce from the reaction with oxygen gas?

a

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