Chemical Names and Formulas: Quiz
Seven questions on naming ionic and molecular compounds and writing their formulas, with explanations.
Chemical Names and Formulas: Quiz
7 questions
MgCl₂ is ionic (magnesium is a metal), so no prefixes are used. Magnesium forms only Mg²⁺, so no Roman numeral is needed either.
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Answer: magnesium chloride
MgCl₂ is ionic (magnesium is a metal), so no prefixes are used. Magnesium forms only Mg²⁺, so no Roman numeral is needed either.
Na⁺ and SO₄²⁻: two sodium ions balance one sulfate ion, 2 × (+1) + (−2) = 0. Na₂S is sodium sulfide.
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Answer: Na₂SO₄
Na⁺ and SO₄²⁻: two sodium ions balance one sulfate ion, 2 × (+1) + (−2) = 0. Na₂S is sodium sulfide.
Al³⁺ and O²⁻: 2 × (+3) + 3 × (−2) = 0, so Al₂O₃.
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Answer: Al₂O₃
Al³⁺ and O²⁻: 2 × (+3) + 3 × (−2) = 0, so Al₂O₃.
Oxide is O²⁻, so copper must be +2 for the compound to be neutral. The Roman numeral goes straight after the metal: copper(II) oxide.
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Answer: copper(II) oxide
Oxide is O²⁻, so copper must be +2 for the compound to be neutral. The Roman numeral goes straight after the metal: copper(II) oxide.
NH₄⁺ and PO₄³⁻: three ammonium ions balance one phosphate ion, 3 × (+1) + (−3) = 0. The ammonium ion is bracketed because there are three of it.
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Answer: (NH₄)₃PO₄
NH₄⁺ and PO₄³⁻: three ammonium ions balance one phosphate ion, 3 × (+1) + (−3) = 0. The ammonium ion is bracketed because there are three of it.
Nitrogen and oxygen are both non-metals, so use prefixes: di (2) nitrogen, tetra (4) oxygen, with the "a" dropped before "oxide".
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Answer: dinitrogen tetroxide
Nitrogen and oxygen are both non-metals, so use prefixes: di (2) nitrogen, tetra (4) oxygen, with the "a" dropped before "oxide".
Ca²⁺ needs two OH⁻ ions. The brackets show that the subscript 2 applies to the whole OH group; CaOH₂ would mean one O and two H.
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Answer: Ca(OH)₂
Ca²⁺ needs two OH⁻ ions. The brackets show that the subscript 2 applies to the whole OH group; CaOH₂ would mean one O and two H.