If HA, an acid, is 15 percent dissociated in a 2.00 molar solution, what is the Ka for the solution? A.5.96 × 10-3 molar
B. 9.38 × 10-3 molar
C. 0.76 × 10-3 molar
D. 5.96 × 103 molar

hope you got the answer

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