Below is a list of functional groups that we will use a lot in this class. for each label, draw the functional group, then circle the polar bonds in each.

Carboxylic acid, Methyl, Amine, Hydroxyl and Phosphate functional groups are present and drawn in the figure below.

Polar bonds are found in carboxylic, Hydroxyl and phosphate functional group.

Explanation:

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