An organic compound, x, will react with calcium metal to produce a salt with the empirical formula cac4h4o4. what could be the identity of x? 1 ethanoic acid 2 butanedioic acid 3 2-methylpropanedioic acid

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

c. 4.54 x 10–12 j happens to be correct