The standard enthalpy change of solution for ammonium nitrate, NH4NO3 , is +25.7 kJ mol–1. (a) Calculate the value for the standard entropy change in the surroundings, ∆Ssurroundings , when ammonium nitrate dissolves in water at 298 K.
Include a sign and units with your answer.

(b) Explain what can be deduced from your answer in (a) about the sign and the value of the standard entropy change in the system, ∆Ssystem , when NH4NO3 dissolves.

b..

is the correct one

explanation:

covalent bonds form as valence electrons are shared between two atoms. lewis structures and structural formulas are common ways of showing the covalent bonding in organic molecules. formal charge describes the changes in the number of valence electrons as an atom becomes bonded into a molecule.

the correct answer to this question is 2

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