What is ion exchange?
Could you elaborate on the concept of ion exchange in a concise yet comprehensive manner? Ion exchange is a process that involves the substitution of ions between two electrolytes, often through the use of ion exchange resins or membranes. Could you provide a basic understanding of its applications, particularly in the field of chemistry, water treatment, and potentially in emerging technologies such as batteries or fuel cells? Additionally, how does this process work at a molecular level, and what are some of the key factors that influence its efficiency?