bond. Water is a polar solvent. The oxygen atom, being more electronegative, attracts the electron cloud toward itself. As the electron cloud is pulled by the oxygen atom, it carries a partial negative charge, and the hydrogen atoms carry a partial positive charge. This partial separation of charges in the water molecule makes it polar. Which intermolecular forces contribute to the dissolution of NaCl in water

NaCl and water: Ion - Dipolo forces

NaCl and Hexane: Ion-ion force between Na+ and Cl− ions and London dispersion force between two hexane molecules

Explanation:

NaCl and water:

The ion-dipole force is established between an ion and a polar molecule.  Polar molecules are dipoles, they have a positive end and a negative end.

H2O has an important charge separation in its atoms (the H has a positive partial charge and the O has a negative partial charge) and this causes permanent electrical dipoles in the water molecules.

Sodium chloride is an ionic compound formed of positive and negative charge ions, Na + and Cl-. Depending on their charge, these ions will be attracted to opposite charges in the water molecules (H attracts chloride ions and O attracts sodium ions), causing the salt to dissolve in water.

Explanation:

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