Final answer:
To calculate the moles of NaCl in a halite crystal, we must convert the crystal's mass using the molar mass of NaCl, and then determine the number of ions present. A crystal containing 0.072 moles of NaCl would have 0.14 moles of ions due to dissociation into Na+ and Cl- ions. This reflects the stoichiometry and crystalline structure of halite.
Step-by-step explanation:
To find the number of moles of NaCl in a crystal of halite, we need to first determine the mass of the halite crystal and consider its molar mass. Halite, which is naturally occurring sodium chloride, forms a crystalline structure that must be analyzed at the atomic level to see the organized sodium (Na+) and chloride (Cl-) ions.
Step 1: Converting grams to moles of NaCl
To convert from grams to moles, we use the molar mass of NaCl as the conversion factor. The molar mass of NaCl is approximately 58.44 g/mol. If we had, for instance, a mass of 4.192 grams of halite, we would calculate the moles of NaCl as follows:
4.192 g NaCl × (1 mol NaCl/58.44 g) = 0.072 mol NaCl
Step 2: Determining the number of moles of ions in NaCl
Since NaCl dissociates into two ions (Na+ and Cl-), for every 1 mole of NaCl, there will be 2 moles of ions in a solution. Based on our previous result, a halite crystal containing 0.072 moles of NaCl would yield:
0.072 mol NaCl × (2 mol ions/1 mol NaCl) = 0.14 mol ions
True Regularity in Halite's Crystalline Structure
Naturally occurring halite does not always appear as neat as diagrams suggest, but modern techniques allow us to observe the regular pattern of ions comprising the crystal lattice. These organized ions demonstrate the stoichiometry inherent in the crystal of NaCl, reflecting the chemical composition of halite.