Which of the following statements accurately describe the atoms in the image, and why? А
These atoms are all ions of carbon, because they have the same number of electrons.
B
These are atoms of different elements because they have different numbers of protons in the nucleus.
С
These atoms are all isotopes of carbon, because they have a different number of neutrons in the nucleus.
D
These are atoms of different elements because they have different numbers of neutrons in the nucleus.

h let me think

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