The seawater of puget sound off the coast of oregon has a salinity of about 24 ppt. what weight of salt is there in 1,000g of seawater?

The given salinity is 24ppt

The relation between salinity and grams is

it means there is 24 parts of salt per 1000 parts of water

ppt: parts per thousand

Or

there is 24 grams of salt per 1000g of water

thus the value 24 ppt signifies that there is 24g of salt dissolved in 1000g or 1kg of water

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