Final answer:
Semi-permeable membranes, influenced by size and the Coulomb force, prevent the passage of Na⁺ and Cl⁻ ions due to their electrical charge and non-lipid solubility, requiring specialized transport proteins for their movement.
Step-by-step explanation:
The membrane that disallows the passage of Na⁺Cl⁻ ions is called a semi-permeable membrane, which can be characterized by a certain Molecular Weight Cut Off (MWCO) value. For instance, a 200 MWCO membrane will block the passage of molecules or complexes greater than 200 Daltons (molecular weight units). Since Na⁺ and Cl⁻ ions have a much lower molecular weight, they are not blocked due to their size but due to their electronic charge and the fact that they are not lipid soluble.
The Coulomb force contributes to this impermeability by creating a layer of positive charge outside and negative charge inside the membrane, thus creating a voltage across the cell membrane that prevents the passage of these ions. Hence, membranes are specifically designed to control the entry and exit of substances, relying on both molecular size and charge, where the transport of impermeable ions like Na⁺ and Cl⁻ require specialized transport proteins.