Study Guide

Question 1

Write chemical formulas.

Question 2

Determine the total number of each type of atom in a chemical formula.

Question 3

Classify compounds as ionic or molecular.

Answer 3

Ionic compounds : formed when a metal and non metal
Molecular compounds : formed from two or more non-metals

Question 4

Write formulas for ionic compounds and molecular compounds (including acids).

Question 5

Name ionic compounds and molecular compounds (including acids).

Question 6

Name ionic compounds and molecular compounds (including acids).

Question 7

Calculate formula mass and molar mass.

Answer 7

Formula mass = (# of atoms of first element)(amu first element) + (# of atoms of second element)(amu of second element) + …

Molar mass = (# of atoms of element)(amu of element)

Question 8

Convert between grams, moles, and number of atoms/molecules/formula units, including, for
example, between grams of a compound and number of atoms or molecules and between
grams/moles of a compound and grams/moles of a constituent element

Answer 8

Grams <—-molar mass—-> moles (of atom or compound)
Moles<——avogadro’s number—-> particles (atoms, molecules, formula units)

g AB —molar mass AB—> mole AB —mole AB: mole A —-molar mass A—> g A

Question 9

Determine the mass percent of each element in a given compound.

Answer 9

Mass percent of element = (mass of element/ mass of the compound) X 100

Use as conversion factor
Xg element/ Yg compound
Or
Yg element/ Xg compound

Question 10

Determine an empirical formula from experimental data (see Practice Problems).

Answer 10

-Convert mass of each element into moles
-Divide the moles of each element by the smallest number of moles
-if the subscription are no while numbers, multiply all the subscripts by a small whole number to arrive to a whole number subscripts

Question 11

Calculate a molecular formula from an empirical formula and molar mass.

Question 12

Identify evidence of a chemical reaction.

Answer 12

Transformation of one or more substance into different substances
-Evidence
1.Formation of a solid
2.Formation of a gas
3.Color change
4.Temperature changes
5.Emission of light when chemical’s are contact w/ each other

Question 13

Write balanced chemical equations.

Question 14

Determine if a compound is soluble (solubility table will be provided).

Question 15

Determine whether a precipitation reaction will occur given two reactants, and, if so, predict
the products formed.

Answer 15

Precipitation reaction are reactions that form a solid

Question 16

Write balanced molecular, complete ionic, and net ionic equations.

Answer 16

Molecular equations -> a chemical equation that shows the complete formula for every compound in the reaction
Complete ionic equations -> shows reactants and products as they are in solution dissociate ( Fe 3+ (aq) + 3Cl- (aq)) ☆ do not dissociate solids, molecular compounds ( H2O, H2, CO2, SO2, NH2, SI)
Net ionic equation: shows only the substances that participate in the reaction

Question 17

Identify spectator ions.

Answer 17

Ions which don’t participate in a chemical reaction, they remain unchanged on both sides of the chemical equation

Question 18

Identify and write balanced chemical equations for acid–base reactions

Answer 18

An acid base reaction is a reaction, an acid and a base react to form a salt (an ionic compound where the cation comes from the base and the anion came from the acid) &water

Question 19

Identify and write balanced chemical equations for gas evolution reactions.

Answer 19

A gas evolution is one in which gas i formed as a product

Question 20

Identify redox reactions.

Answer 20

An oxidation reduction reaction is a reaction involving a transfer of electrons

Question 21

Identify and write balanced chemical equations for combustion reactions.

Answer 21

When balancing combustion reactions involving hydrocarbons, balance carbon first, then hydrogen, and oxygen last

Question 22

Classify chemical reactions (e.g., combustion reaction, double-displacement reaction, etc.).

Answer 22

-Synthesis/combination reaction: two or more substances (element or compound) react to form a single product (A+B -> AB)
-Decomposition reaction: a single compound breaks apart to form two or more compounds (may require energy) (AB -> A+B)
-Single displacement reaction: one element displaces another (A + BC -> AC + B)
-Double-displacement reaction: two different substances exchange places to form two new compounds (AB + CD -> CB + AD)