What mass of a 0.583 molar solution of iron(III) nitrate is needed to obtain a) 0.0200 moles of iron(III) nitrate, b) 0.0500 moles of Fe3+ ions, c) 0.00300 moles of nitrate ions? please show work?

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