Why ionic solids dissolve: Common table salt (NaCl) dissolves readily in water primarily because water molecules…

Introduction / Context: Solubility of ionic solids like NaCl in water is a cornerstone concept in general chemistry. Water’s polarity enables it to stabilize separated ions, overcoming lattice energy and allowing dissolution.

Given Data / Assumptions:

• Water is a polar solvent with a bent geometry and significant dipole moment.
• Sodium chloride consists of Na+ and Cl– ions in a crystal lattice.
• Dissolution requires hydration energy to offset lattice energy.

Concept / Approach: The partial negative charge of oxygen in H2O orients toward cations; the partial positive charges on hydrogens orient toward anions. These ion–dipole interactions generate hydration shells that stabilize ions in solution. We often describe the ensemble as a solvation or hydration sphere.

Step-by-Step Solution: Recognize polarity → water's dipole aligns with ions. Form hydration shells → multiple water molecules coordinate around Na+ and Cl–. Energy balance → hydration (solvation) energy compensates for lattice energy. Result → crystal dissociates into solvated ions; salt dissolves.

Verification / Alternative check: Conductivity measurements increase upon dissolution due to mobile ions; spectroscopic and simulation studies visualize hydration shells around ions.

Why Other Options Are Wrong: Nonpolar covalent bonding (option B) does not occur; option C denies directed ion–dipole stabilization; option D suggests electron sharing to form covalent bonds, which is not the dissolution mechanism; exclusive hydrogen bonding to chloride (option E) is incomplete and misleading.

Common Pitfalls: Calling these interactions “hydrogen bonds to ions”; the correct term is ion–dipole interactions, though water can hydrogen bond to other water molecules in the hydration shell.

Final Answer: form strong hydration shells via ion–dipole interactions around both positive and negative ions.