The table below gives the atomic mass and relative abundance values for the three isotopes of element M. Relative abundance (%) Atomic mass (amu) 78.99 23.9850 10.00 24.9858 11.01 25.9826 What is the average atomic mass (in amu) of element M? 2.86 5.36 24.30 24.98

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

explanation:

a