CHM Ch. 3
Describe the difference between a molecular formula and an empirical formula. Give an example.
A molecular formula is the exact number of each type of atom necessary to build a specific molecule. An empirical formula is simply the smallest whole number ratio between atoms in a compound. For example, C2H4 is the molecular formula for ethene. The empirical formula for ethene is CH2, the smallest whole number ratio between the atoms.
Describe the difference between ionic and molecular compounds. Give an example of each.
An ionic compound is formed between a metal and a nonmetal (or polyatomic ions) and is held together through the attraction of opposite charges. An example is NaCl. A molecular compound is usually formed between 2 or more nonmetals and is held together through the sharing of electrons between atoms. An example is CO2
How can one compound contain both ionic and covalent bonds? Give an example.
An ionic compound that contains a polyatomic ion, such as NaNO3, has both ionic bonds (that hold the sodium and nitrate ions together) as well as covalent bonds (that hold the atoms within the nitrate ion togeth
Describe the difference between an atomic element and a molecular element.
Atomic elements exist in nature with a single atom at their basic unit; molecular elements exist in nature with more than one atom as their basic unit.
How do you get the empirical formula?
Find the GCF then divide all exponents by that number.
Can you predict the chemical formula for a covalent compound between nitrogen and oxygen? Explain your answer.
No, since nitrogen and oxygen are both nonmetals, they combine by sharing electrons. This can be done in multiple different ways. Some possible compounds are N2O, N2O3, NO2.
Why aren't prefixes used in naming ionic compounds?
The charges on the ions dictate how many must be present to form a neutral unit. Molecular compounds do not have such constraints and therefore must use prefixes to denote the number of atoms present.
A covalent bond is best described as
the sharing of electrons between atoms
An ionic bond is best described as
the transfer of electrons from one atom to another
