8. if i have 34 grams of feo, how many grams of oxygen were synthesized?
fe + o2 → feo

34 gram of FeO produced 8 gram of oxygen.

Explanation:

Given data:

Mass of FeO = 34 g

Mass of oxygen = ?

Solution;

Chemical equation:

2FeO → 2Fe + O₂

Number of moles of FeO:

Number of moles = mass/ molar mass

Number of moles = 34 g /71.8 g/mol

Number of moles = 0.5 mol

Now we will compare the moles of FeO with oxygen:

             FeO       :       O₂

                2         :        1

                0.5      :      1/2 × 0.5 = 0.25

Mass of oxygen:

Mass = number of moles × molar mass

Mass =  0.25 mol × 32 g/mol

Mass = 8 g

So 34 gram of FeO produced 8 gram of oxygen.

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