Chem 103: Module 4 UPDATED ACTUAL Exam Questions and CORRECT Answers

Chem 103: Module 4 UPDATED ACTUAL
Exam Questions and CORRECT Answers
Avogadro's number - CORRECT ANSWER -6.022 x 10^23 atoms = 1 mole



1 u = ___ g - CORRECT ANSWER -1.661 x 10 ^-24 g



formula mass - CORRECT ANSWER -the sum of the average atomic masses of each atom
represented in the chemical formula and is expressed in atomic mass units.
--The formula mass of a covalent compound is also called the molecular mass.


The chemical identity of a substance is defined by - CORRECT ANSWER -the types and
relative numbers of atoms composing its fundamental entities (molecules in the case of covalent
compounds, ions in the case of ionic compounds).


A compound's percent composition provides - CORRECT ANSWER -the mass percentage
of each element in the compound.


calculate the formula mass of a substance by - CORRECT ANSWER -summing the
average atomic masses of all the atoms represented in the substance's formula.


A mole is defined as - CORRECT ANSWER -the amount of substance containing the
same number of discrete entities (such as atoms, molecules, and ions) as the number of atoms in
a sample of pure 12-C weighing exactly 12 g


percent composition - CORRECT ANSWER -the percentage by mass of each element in a
compound
i.e. mass X / mass compound x 100%