4Al2O3 +9Fe → 3Fe3O4 + 8AI If there are 10.2 grams of Al2O3 and 11.2 grams of Fe, which statement
identifies the limiting reagent in this reaction and best supports that claim?
A. Fe is the limiting reagent, because 9 moles of Fe are required for
every 4 moles of Al2O3.
B. Al2O3 is the limiting reagent, because there are only 0.1 moles of
Al2O3 and twice as many moles of Fe.
O C. Al2O3 is the limiting reagent, because there are fewer grams of it
present
D. Fe is the limiting reagent, because the reaction requires nearly
twice the mass of Fe as of Al2O3,

answer: they produce more slow than unicellular organisms.

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