CHEM 121 Module 2 Exam – COMPLETE QUESTIONS WITH CORRECT DETAILED
ANSWERS || 100% GUARANTEED PASS <BRAND NEW VERSION 2025>
Description:
This CHEM 121 Module 2 Exam study guide includes verified questions with 100% correct
answers covering atomic structure, periodic trends, chemical bonding, and molecular geometry.
Ideal for introductory chemistry students preparing for unit assessments.
Keywords:
CHEM 121 module 2
introductory chemistry
atomic structure quiz
chemical bonding
periodic trends
molecular geometry
verified chemistry answers
CHEM 121 exam prep
unit 2 chemistry test
college chemistry study guide
How to calculate molecular weight? - ANSWER add up the individual atomic weights of
each element. Don't forget to multiply an element's atomic weight by how many atoms of that
element there are.
,What is a Mole and how to you solve for it? - ANSWER The amount of chemical reaction of
a compound. Moles= gram/ molecular weight
Percent of an element - ANSWER = (weight of an individual element/ MW of the whole
compound) x 100
How to solve for Empirical Formula - ANSWER 1. Divide each each % of an element (this
is provided) by it's atomic weight
2. Using the results from step 1, divide each of those results by the smallest number given from
that set (round answers to nearest whole number) ( if one of the answers ends in .25- 1/4, .333-
1/3, .5- 1/2, .666- 2/3, .75- 3/4 multiply all of the answers by the denominator)
3. The whole numbers become the subscripts. aka the number of atoms in the element
Combination reaction (synthesis) - ANSWER a chemical change in which 2 or more
substances react to form a single new substance
Decomposition reaction - ANSWER a chemical change in which a single compound is
broken down into two or more products
, Combustion reaction - ANSWER A reaction in which a hydrocarbon combines with oxygen
to produce carbon dioxide and water
What is a double replacement reaction - ANSWER A reaction in which 2 ionic compounds
exchange their ions to form a non-ionic compound product either as a solid insoluble precipitate,
gas, or molecular compound
What is a single replacement reaction - ANSWER A reaction in which a metallic element
reacts with a metallic ionic compound to replace the metal ion from the ionic compound as a
metal element.
Same goes for nonmetal elements and nonmetal ionic compounds
Compounds that are insoluble in water - ANSWER Sulfide ion, Hydroxide ion, Carbonate
ion, Phosphate ion. But is soluble if combined with NH4 (ammonium) or group i. (sulfide is also
insoluble when combined with group ii)
Compounds that are soluble in water - ANSWER Ammonium ion, Group i and ii ions,
[Chloride ion, Bromide ion, Iodine ion] (unless combined with Ag Silver, Pb Lead, Hg Mercury)
, Nitrite ion, Acetate ion, Sulfate ion (unless combined with Sr, Pb lead, Ba Barium, Hg
Mercury)
ANSWERS || 100% GUARANTEED PASS <BRAND NEW VERSION 2025>
Description:
This CHEM 121 Module 2 Exam study guide includes verified questions with 100% correct
answers covering atomic structure, periodic trends, chemical bonding, and molecular geometry.
Ideal for introductory chemistry students preparing for unit assessments.
Keywords:
CHEM 121 module 2
introductory chemistry
atomic structure quiz
chemical bonding
periodic trends
molecular geometry
verified chemistry answers
CHEM 121 exam prep
unit 2 chemistry test
college chemistry study guide
How to calculate molecular weight? - ANSWER add up the individual atomic weights of
each element. Don't forget to multiply an element's atomic weight by how many atoms of that
element there are.
,What is a Mole and how to you solve for it? - ANSWER The amount of chemical reaction of
a compound. Moles= gram/ molecular weight
Percent of an element - ANSWER = (weight of an individual element/ MW of the whole
compound) x 100
How to solve for Empirical Formula - ANSWER 1. Divide each each % of an element (this
is provided) by it's atomic weight
2. Using the results from step 1, divide each of those results by the smallest number given from
that set (round answers to nearest whole number) ( if one of the answers ends in .25- 1/4, .333-
1/3, .5- 1/2, .666- 2/3, .75- 3/4 multiply all of the answers by the denominator)
3. The whole numbers become the subscripts. aka the number of atoms in the element
Combination reaction (synthesis) - ANSWER a chemical change in which 2 or more
substances react to form a single new substance
Decomposition reaction - ANSWER a chemical change in which a single compound is
broken down into two or more products
, Combustion reaction - ANSWER A reaction in which a hydrocarbon combines with oxygen
to produce carbon dioxide and water
What is a double replacement reaction - ANSWER A reaction in which 2 ionic compounds
exchange their ions to form a non-ionic compound product either as a solid insoluble precipitate,
gas, or molecular compound
What is a single replacement reaction - ANSWER A reaction in which a metallic element
reacts with a metallic ionic compound to replace the metal ion from the ionic compound as a
metal element.
Same goes for nonmetal elements and nonmetal ionic compounds
Compounds that are insoluble in water - ANSWER Sulfide ion, Hydroxide ion, Carbonate
ion, Phosphate ion. But is soluble if combined with NH4 (ammonium) or group i. (sulfide is also
insoluble when combined with group ii)
Compounds that are soluble in water - ANSWER Ammonium ion, Group i and ii ions,
[Chloride ion, Bromide ion, Iodine ion] (unless combined with Ag Silver, Pb Lead, Hg Mercury)
, Nitrite ion, Acetate ion, Sulfate ion (unless combined with Sr, Pb lead, Ba Barium, Hg
Mercury)
