hydrocarbon is quite exothermic (think gasoline, kerosene, burning candles, etc.).21 . D
This is the only reaction that shows an acid and a base as reactants. Option C shows the
hydrolysis of a weak base—nothing is being neutralized.22 . A
Silver ions and chloride ions combine in solution to form a precipitate of silver chloride. In a
precipitation reaction, aqueous ions combine to form an insoluble solid.23 . E
In a decomposition reaction, a single reactant falls apart (usually under heat) to form two or
more products. In this case, solid calcium carbonate is heated to form carbon dioxide gas,
which escapes, leaving solid calcium oxide.25. Part B
101 . T, T
Draw the Lewis structures of the two compounds: N 2 has a triple bond between the two
nitrogen atoms, while N 2 H 4 has a single bond. Single bonds are longer and weaker than double
or triple bonds between the same atoms. The atomic radius of H is smaller than the atomic
radius of N, but this has nothing to do with the bond lengths in these molecules.102 . T, F
The electrons occupy only certain energy levels; therefore only certain wavelengths are
absorbed or emitted by electrons moving between these energy levels.
103 . T, F
Even if it were true that iodine forms stronger covalent bonds, this would still not be the
correct explanation: when molecular substances change phases from solid to liquid to gas,
only intermolecular interactions are broken, not covalent bonds.
104 . T, T
H 2 O has a very high boiling point compared to other Group IV hydrides because of the strong
hydrogen bonds between water molecules. If not for the hydrogen bonding, the greater