Category 1: Empirical & Molecular Formula
Question: What is an empirical formula?
Answer: The simplest, lowest whole-number ratio of atoms in a compound
If a compound has an empirical formula of CH2and a molar mass of 84 g/mol what is its molecular formula?
C6H12
Question: What happens to atomic radius as you move down a group on the periodic table?
It increases (due to additional electron shells).
How does a neutral atom become a cation?
By losing one or more electrons.
How does a neutral atom transform into an anion?
By gaining one or more electrons.
Question: What does a molecular formula represent?
Answer: The actual, exact number of atoms of each element in a single molecule of a compound.
Question: What are the horizontal rows on the periodic table called?
Periods
What is electronegativity?
The measure of an atom's ability to attract shared electrons within a chemical bond.
What electrical charge does a cation carry?
A positive charge.
What type of electrical charge does an anion carry?
A negative charge.
Question: What is the empirical formula of glucose C6H1206
CH2O
Which group of elements is virtually unreactive due to having full valence electron shells?
Noble gases (Group 18).
How do electronegativity and ionization energy change as you move left-to-right across a period?
They both generally increase.
Do metals or nonmetals typically form cations?
Metals.
Do metals or nonmetals typically gain electrons to form anions?
Nonmetals.
Question: How do you calculate the integer multiplier n needed to convert an empirical formula to a molecular formula
molecular mass/ emperirical mass
What are elements called if they lie along the staircase boundary line and exhibit properties of both metals and nonmetals?
Metalloids (or semimetals).
What is first ionization energy?
The energy required to remove the outermost electron from a neutral, gaseous atom
What charge does an aluminum atom (Group 13) form when it loses its valence electrons to become stable?
+3
What charge does a fluorine atom (Group 17) form when it gain its valence electrons to become stable?
-1
If a compound has an empirical formula of CH2 and a molar mass of 84 g/ mol what is its molecular formula?
c= 12 g/mol
h= 1 g/mol
6
What is the family name given to Group 2 metals on the periodic table?
Alkaline earth metals.
Which element has the highest electronegativity, and which alkali metal has the lowest?
Fluorine has the highest; Francium (or Cesium) has the lowest.
What charge does an Magnesium atom (Group 2) form when it loses its valence electrons to become stable?
+2
What charge does a oxigen atom (Group 16) form when it gain its valence electrons to become stable?
-2