l>

Classifying Electrolytes

Electrolytes are substances which, once liquified in water, break up intocations (plus-charged ions) and anions (minus-charged ions). We say they ionize.

You are watching: Which of the following substances is a weak electrolyte?

Strong electrolytes ionize totally (100%), while weak electrolytesionize just partly (normally on the order of 1–10%). That is, the primary speciesin solution for solid electrolytes are ions, while the primary specie in solution for weak electrolytes is the un-ionized compound itself.Strong electrolytes fall into 3 categories: solid acids,solid bases, and salts. (Salts are periodically additionally dubbed ionic compounds, yet really strongbases are ionic compounds too.) The weak electrolytes include weak acids and also weak bases.Instances of strong and weak electrolytes are provided below:
Strong Electrolytes strong acidsHCl, HBr, HI, HNO3, HClO3, HClO4, and also H2SO4 strong basesNaOH, KOH, LiOH, Ba(OH)2, and Ca(OH)2 saltsNaCl, KBr, MgCl2, and also many type of, many kind of moreWeak Electrolytes weak acidsHF, HC2H3O2 (acetic acid), H2CO3 (carbonic acid), H3PO4 (phosphoric acid), and also many more weak basesNH3 (ammonia), C5H5N (pyridine), and also numerous more, all containing "N"

Being Able to Classify Electrolytes Is Critical

As chemists, we must have the ability to look at a formula such as HCl or NaOH and also quickly knowwhich of these classifications it is in, because we have to be able tounderstand what we are working through (ions or compounds) as soon as we are working withchemicals. We should know, for example, that a bottle labeled "NaCN" (a salt) really containsno NaCN, rather Na+ and CN–, or that a bottle labeled "HCN" (a weak acid) is principally HCNvia a tiny amount of H+ and also CN– additionally current. The difference in between simply opening a bottle labeled "HCN" and 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 and is just transfered in solid or solution form. Nonetheless, it is cyanide ion, CN–, that is the killer. (It locks onto the Fe3+ in hemoglobin, resulting in less oxygen to obtain to your brain.) Cyanide is present in both bottles, and if it is transfered to your bloodstream either as CN– or as HCN, it will kill you.

Six Steps for Categorizing Electrolytes

So just how do we categorize compounds based on their formula? One handy strategy is outlined below:
Step 1Is it among the seven strong acids?Step 2Is it of the develop Metal(OH)n? Then it"s a solid base.Step 3Is it of the create Metal(X)n? Then it"s a salt.Tip 4Does it"s formula start with "H"? It"s probably a weak acid.Step 5Does it have a nitrogen atom? It may be a weak base.

See more: Did You Wake Up On The Wrong Side Of The Bed, Waking Up On The 'Wrong Side Of The Bed'

Step 6Namong those? Call it a nonelectrolyte.
Note that there are ambiguities right here beginning in Step 4. That"s just the means it is. To recognize whether a substance is a weak acid or weak base you have to understand even more than the molecular formula, particularly for compounds containing carbon. (A structural formula, which reflects the in-depth relations of atoms is frequently vital.)SummaryIn summary, understand the even more widespread element names and also signs, memorize the salso solid acids, be able to spot a metal (understand at leastern wbelow they are on theroutine table), memorize at least a few of the more common weak acids and weak base,and also you will certainly be in good form. YOU CAN DO IT!