Science, Tech, Math › Science Ionic Compounds Nomenclature Quiz See If You Can Name These Ionic Compounds Take this quiz to see if you know how to name ionic compounds and write their formulas. SSPL / Getty Images Science Chemistry Molecules Basics Chemical Laws Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. Learn about our Editorial Process Updated on March 08, 2017 1. Let's start with an easy one. The correct formula for sodium chloride (table salt) is: NaCl Na₂Cl NaCl₂ Na₂Cl₂ Correct Wrong Start by looking up (or remembering) the element symbols. The first part of the name is "sodium", so you know you're looking for an element and not a cation. The symbol is Na. The second part of the name has an -ide ending, which means you're dealing with a simple element anion. The symbol for chlorine is Cl. Finally, you need to know the oxidation states of sodium and chlorine, which you get by knowing the charges on the element groups (+1 for sodium and other elements in it's group and -1 for chlorine and elements in the same group). The transition metals and nonmetals can be trickier because they are more likely to have multiple oxidation states. Since the positive and negative charges of sodium and chlorine cancel each other out, you get NaCl. 2. What are the ions in sodium chloride? Na, Cl Na⁺, Clˉ Naˉ, Cl⁺ Na₂, Cl₂ Correct Wrong You need to recognize the ions in an ionic compound. The name gives you this information. The cation is always given first in a name, followed by the anion. So, you know the first part will always have a positive charge and the second part will have a negative charge. To know the charges, look at the periodic table. Sodium is an alkali metal, so you know it has a +1 charge, while chlorine is a halogen, so you know it has a -1 charge. 3. NaClO is named: sodium chlorite sodium chlorate sodium hypochlorite sodium hypochlorate Correct Wrong For this question, it helps to know the common cations and anions. You can look them up or memorize them. The cation is sodium and the ClO is called hypochlorite, which has a -1 charge. 4. What is the formula for chromium (III) phosphate? CrPO₃ Cr₂PO₄ Cr₂(PO₄)₃ CrPO₄ Correct Wrong In most cases, you'll be given the oxidation state of transition metals, like chromium, because their atoms can exhibit several valences. Since you know the charge on chromium is 3+ and (hopefully) know the formula for phosphate and that its charge is 3-, you need to figure out how many chromium cations and phosphate anions you need to balance each other out. The smallest number that works is one of each. You don't put subscripts of 1 in chemical formulas. 5. What is the oxidation number of the chromium in chromium (III) phosphate?: -2 +3 +4 -3 Correct Wrong Chromium(III) phosphate has the chemical formula CrPO4. The name of an ionic compound also gives you information about the oxidation numbers of the elements. You should know the Roman numerals for 1 (I), 2 (II), 3 (III), 4 (IV), 5 (V), and 6 (VI). While there are higher oxidation numbers, they are less common. 6. Plaster of Paris is calcium sulfate. What is the formula of calcium sulfate? CaSO₂ CaSO₃ CaSO₄ Ca₂SO₄ Correct Wrong Based on what you have learned, this one should be easy. Calcium is an alkaline earth, so its charge is 2+ and sulfate is SO42-. If you had to look up sulfate, you might want to try to remember it. It's very common! 7. Identify the ions in calcium sulfate. Ca²⁺, SO₄²⁻ Ca, SO₄ Ca⁺, SO₄ˉ Ca²⁺, SO₄ˉ Correct Wrong This is just breaking down the cations and anions in the formula. Since the question asked for ions, they have charges, which are indicated as superscripts above the formulas. 8. Ammonium nitrate is used as a fertilizer and as an explosive. What is the formula of ammonium nitrate? NH₃NO₂ NH₃NO₃ NH₃NO₃ NH₄NO₃ Correct Wrong It's the same deal, except this time the cation is a polyatomic ion rather than an atomic ion. Ammonium is NH4+ while nitrate is NO3-. 9. The ionic compound LiBrO₂ is named: lithium bromide lithium bromate lithium bromite lithium (II) bromate Correct Wrong The "lithium" part of this name is easy, but if you missed this question, you may want to review when to end a name with -ide, -ite, and -ate. 10. The formula for potassium permanganate is: KMnO KMnO₂ KMnO₄ K₂MnO₂ Correct Wrong Permanganate has the "per" prefix and "ate" suffix. The -ate ending means there are two oxyanions that may be formed with manganese and that you are dealing with the one with the greater number of oxygen atoms (contrast with -ite). The per- prefix means, "oh wait, it's not just 2 oxygen atoms that could be bound, but as many as four, and you're dealing with four". The other option would have been a prefix of hypo-. It takes some practice to recognize these, so if you got this one right, you're a pro! Ionic Compounds Nomenclature Quiz You got: % Correct. You Need More Ionic Nomenclature Practice LAGUNA DESIGN / Getty Images Good work! You made it through the quiz, so you should understand more about the rules of ionic compound nomenclature. However, you missed a few questions, so it might help to review the naming rules. Another helpful resource is this table of common polyatomic ions and their charges. Ready for another quiz? See how well you do with these metric to metric unit conversions. Share Your Results Ionic Compounds Nomenclature Quiz You got: % Correct. You Know a Lot About Ionic Compound Nomenclature Georgijevic / Getty Images You rocked this quiz! It's obvious you've studied how to name ionic compounds and write the formulas from the names. You might want to review the rules for naming ionic compounds to make certain you've mastered them. The next step is predicting whether two species will form ionic or covalent bonds. If you're ready for another chemistry quiz, see whether you can balance these chemical equations. Share Your Results