The molar mass of monopotassium phosphate is 136.09 g/mol. how many moles of monopotassium phosphate are needed to make 250.0 ml of 0.15 m monopotassium phosphate?

0.0375 moles

Explanation:

Given that:

Molar mass of monopotassium phosphate = 136.09 g/mol

Given that volume = 250.0 mL

Also,

So, Volume = 250 / 1000 L = 0.25 L

Molarity = 0.15 M

Considering:

Thus, moles of monopotassium phosphate needed = 0.0375 moles

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