Question

Post Lab

Post-Lab Assignment (70 pts) - maximum 4-page lim it the discussions you had during lab, re-work your (8 pts) Based on the evidence you collected and explanation about what you think is occurring at the mole 1. cular-level with the particles in solution hen adding salt (NaCI) into water. Within your response, use some form of the terms dissolution and 'dissociation' which you discussed previously during the lab. Draw a molecular-level picture that accompanies this explanation. Throughout your response, you must cite detailed and specific conductivity evidence/observations from lab that support s) your explanation. You should also use precise terminology in this explanation to distinguish whether you think the particles are molecules atoms, and/or ions.

Answer 1

Sodium chloride (NaCl) dissolves when water molecules continuously attack the NaCl crystal, pulling away the individual sodium (Na⁺) and chloride (Cl^–) ions. This nonstop attack continuous until the whole NaCl crystal disintegrates.

1^st step: The sodium (Na⁺) and chloride (Cl^–) ions must break the force of attraction between them.

2^nd step: The water molecules must break the attraction between them so that they can make room to allow the sodium (Na⁺) and chloride (Cl^–) ions to enter and interact with the water molecules.

3^rd step: The water molecules must strongly attract the sodium (Na⁺) and chloride (Cl^–) ions. This strong attraction is necessary to generate enough energy to supply the 1^st and 2^nd steps.

Molecular level Picture

Macroscopic level Water Sodium ion (Nat NaCl Chloride ion (CI) Oxygen anom Water (H,o) Hydiogen atom Microscopic level t Partially positive Sodium ion sorrounded by water molecules with the partially negative oxygen atom of water pointing towards it. Chloride ion sorrounded by water molecules with the partially positive hydrogen atoms of water pointing towards it.