Na2S
Sodium Sulfide
Write the formula for magnesium chloride
MgCl2
Which type of compound generally has the highest melting point: ionic compounds or molecular compounds?
Ionic
A student names Na₂O as disodium oxide. What's wrong?
Ionic compounds don't use prefixes.
This compound has a high melting point and conducts electricity when dissolved in water. What type of compound is it?
Ionic compound
N2O4
Dinitrogen Tetroxide
Write the formula for carbon dioxide
CO2
Why can molten NaCl conduct electricity while solid NaCl cannot? What is the formula for sulfur trioxide?
The ions are free to move when molten but are fixed in place when solid.
A student writes the formula for calcium nitrate as CaNO₃. Correct it.
Ca(NO₃)₂
This compound is named using prefixes such as di-, tri-, and tetra-. What type of compound is it?
A molecular compound
Sulfuric Acid
Write the formula for iron(III) bromide.
FeBr3
Two compounds dissolve in water. One solution conducts electricity strongly, while the other does not. Which solution is more likely to contain ions?
The solution that conducts electricity strongly.
A student names FeCl₃ as iron chloride. What's the correct name
Roman numeral III to make Iron (III) Chloride
This compound begins with hydrogen and contains the sulfate ion. What type of compound is it, and what is its name?
An acidic compound, sulfuric acid
Pb(C2H3O2)4
Lead (IV) Acetate
Write the formula for hypochlorous acid
HOCl
Which compound would likely have the higher melting point: HCl or NaCl?
NaCl (ionic compounds generally have much higher melting points than acids).
A student names H₂SO₄ as sulfurous acid. Correct the name.
Sulfuric acid
A compound contains hydrogen and a polyatomic ion ending in "-ate." What type of compound is it?
An oxyacid
(NH4)2Cr2O7
Ammonium Dichromate
Write the formula for copper (II) hydrogen carbonate
Cu(HCO3)2
An unknown compound conducts electricity in water but contains no metal. What type of compound is it most likely?
An acidic compound
A student says Iron (III) Sulfate is FeSO4. Correct it.
Fe2(SO4)3
An unknown compound has the properties: dissolves in water, solution conducts electricity, name contains a roman numeral, and it doesn't begin with Hydrogen. What type of compound is it, and what feature of the compound requires the Roman numeral?
It is an ionic compound.
The Roman numeral indicates that the metal can form more than one possible charge (it is a transition metal or another multivalent metal).