Classifying Electrolytes
| Electrolytes are substances which, when dissolved in water, break up intocations (plus-charged ions) & anions (minus-charged ions). We say they ionize. Bạn đang xem: Nacl + koh → naoh + kcl Strong electrolytes ionize completely (100%), while weak electrolytesionize only partially (usually on the order of 1–10%). That is, the principal speciesin solution for strong electrolytes are ions, while the principal specie in solution for weak electrolytes is the un-ionized compound itself.Strong electrolytes fall into three categories: strong acids,strong bases, & salts. (Salts are sometimes also called ionic compounds, but really strongbases are ionic compounds as well.) The weak electrolytes include weak acids and weak bases.  Examples of strong and weak electrolytes are given below: | Strong Electrolytes | strong acids | HCl, HBr, HI, HNO3, HClO3, HClO4, and H2SO4 | strong bases | NaOH, KOH, LiOH, Ba(OH)2, và Ca(OH)2 | salts | NaCl, KBr, MgCl2, and many, many more | Weak Electrolytes | weak acids | HF, HC2H3O2 (acetic acid), H2CO3 (carbonic acid), H3PO4 (phosphoric acid), and many more | weak bases | NH3 (ammonia), C5H5N (pyridine), and several more, all containing "N" |
Being Able to Classify Electrolytes Is Critical
As chemists, we need to be able to look at a formula such as HCl or NaOH và quickly knowwhich of these classifications it is in, because we need to lớn be able toknow what we are working with (ions or compounds) when we are working withchemicals. We need to know, for example, that a bottle labeled "NaCN" (a salt) really containsno NaCN, rather Na+ & CN–, or that a bottle labeled "HCN" (a weak acid) is principally HCNwith a small amount of H+ và CN– also present. The difference between just opening a bottle labeled "HCN" & one labeled "NaCN" could be your life, as HCN, or hydrogen cyanide, is a toxic gas, while CN–, or cyanide ion, being an ion, isn"t a gas & is only transfered in solid or solution form. Nonetheless, it is cyanide ion, CN–, that is the killer. (It locks onto the Fe3+ in hemoglobin, causing less oxygen khổng lồ get to lớn your brain.) Cyanide is present in both bottles, & if it is transfered to lớn your bloodstream either as CN– or as HCN, it will kill you.Six Steps for Categorizing Electrolytes
So how vị we categorize compounds based on their formula? One practical method is outlined below:| Step 1 | Is it one of the seven strong acids? | Step 2 | Is it of the khung Metal(OH)n? Then it"s a strong base. | Step 3 | Is it of the khung Metal(X)n? Then it"s a salt. | Step 4 | Does it"s formula start with "H"? It"s probably a weak acid. | Step 5 | Does it have a nitrogen atom? It may be a weak base. Xem thêm: Quá Trình Bày Quá Trình Phát Triển Của Văn Học Việt Nam Thế Kỷ Xx | Step 6 | None of those? gọi it a nonelectrolyte. |