10. Which set of substances listed is correctly sequenced from strongest to weakest acid?
pH = 3, pH = 2, pH = 9
pH = 7, pH = 8, pH = 9
pH = 8, pH = 10, pH = 14
pH = 1, pH = 3, pH = 6

1,3,6

Explanation: Whenever your pH goes down, the acid becomes stronger.

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