LECTURE 5

Question 1

• Rules in balancing chemical equations

5. Adjust the coefficient of ____ last
6. Check to see that the atoms of all
   elements are balanced

Answer 1

Mono-atomic

Question 2

• Rules in balancing chemical equations
1. Gaseous elements exist as ____ molecules (e.g. H2, O2, N2, F2, Cl2, Br2, I2)
2. Balance first the elements other than oxygen or hydrogen

3. When there are groups of atoms acting as a unit such as a polyatomic ion, it is best to balance them as _____ groups
4. Balance hydrogen or oxygen next and select the one that is present in the ___ number of compounds first

Answer 2

Diatomic
Self-contained
Fewer

Question 3

• Guidelines in balancing chemical equations
1. Subscripts of a compound are ___; they cannot be changed

2. The coefficients used should be the smallest whole numbers possible
3. The coefficients multiplies every number in the formula

Answer 3

Fixed

Question 4

– In reactions between two compounds in aqueous solution, the positive and negative
ions appear to “change partners”

Reaction
AX + BY → AY + BX

Answer 4

Double replacement reaction

Question 5

– Also known as Methathesis Reactions

Answer 5

Double replacement reaction

Question 6

– Reactions in which one element displaces another from a compound

– More active metals displaces less active metals

Reaction
AB + X → XB + A
where X is more active than A

Answer 6

Single replacement reaction

Question 7

– Are those reaction in which a compound decomposes to produce the following:
• Two Elements
• One or more elements and or one or more
compounds
• Two or more Compounds

Reaction
AB → A + B

Answer 7

Decomposition reaction

Question 8

– Reaction in which two or more substances combine to form a compound
• Element + Element — Compound
• Element + Compound—Compound
• Compound + Compound—- Compound

Reaction
A + B → AB

Answer 8

Combination reaction

Question 9

1. • ____
   A + B—- AB
2. _____ Reaction
   AB → A + B
3. _____ Reaction
   AB + X → XB + A
4. _____ Reaction
   AX + BY → AY + BX

Answer 9

Combination reaction
Decomposition reaction
Single replacement reaction
Double replacement reaction

Question 10

– Consists of symbols and formulas
representing a chemical reaction

• ______
– Reacting species written to the left of the arrow
• _____
– Species Formed as a result of the reaction

Answer 10

Chemical equation
Reactants
Products

Question 11

– Acids formed by combination of hydrogen with most of the polyatomic anions

• Naming Convention
– [Root of the Anion] + [-ic or -ous] + [acid]
– Oxyanion ends that ends with
• –ite change to – ous
• – ate change to –ic

Answer 11

Oxyacids

Question 12

are acids composed of hydrogen plus another element

Naming Convention

[Hydro] + [Root of the Anion] + [-ic] + [acid]

Answer 12

Binary acids

Question 13

– The least electronegative element is written first
– The number of atoms of each element is indicated
by the use of Greek Prefixes

Answer 13

Non-metal-non-metal binary compounds

Question 14

– The name has a root taken from the name of the central atom

e.g. Carbonate CO3²
Nitrate NO3
Chlorate ClO3
-

Answer 14

Polyatomic ion

Question 15

• Formula that contains more than one of a
group of atoms that occurs as a unit

e.g. Na2CO³ Sodium Carbonate
KMnO⁴ Potassium Permanganate
CaClO² Calcium Chlorite

Answer 15

Polyatomic compounds

Question 16

Formula Writing & Naming Compounds
To distinguish between compounds with varying
charges

• ____
• [Name metal] (Charge in Roman
Numeral) [non-metal ends with –ide]

• ____
• [Latin name + “ous” or “ic”] ) [non-metal
ends with –ide]

where: ous – lower charge
ic – higher charge

Answer 16

Stock method
Classical method

Question 17

Formula Writing & Naming Compounds

• Metals with Ions of ____ one charge

– Some representative elements and most transition elements can form more than one cation
e.g. Copper chloride is ambiguous

Answer 17

More than

Question 18

Guide for Naming Binary Ionic Compound

• _____ Compounds
– [Name of Metal] [Non-Metal ends with -ide]

• Formula writing
– Cross Charge Method

• ____ are used in formulas when atom ratios are ____

Answer 18

Ionic binary
Cross change method
Subscripts
Not 1:1

Question 19

GUIDE FOR NAMING BINARY IONIC BONDS
• The ____ is always listed before the anion
• The Cation – Anion ratio must give a net charge of ___
• The ratio is always expressed by the ____ whole numbers
• The ____ English name of the metal is used
• The name of the anion includes only the English root plus –____

Answer 19

Cations
Zero
Smallest
Unchanged
Ide

Question 20

– Composed of just two elements

• Metal Cation + Non Metal Anions
–Example: NaCl, K2S

Answer 20

Metal-nonmetal binary compounds (binary ionic compound)

Question 21

• Shows the distribution of electrons in the outermost shell of the atom as the atoms are united to each other

Answer 21

Lewis electronic formula

Question 22

• Represents atoms as lines or bonds to represent valence

Answer 22

Structural formula

Question 23

• Based on the actual number of atoms that comprise a
molecule of that compound

Answer 23

Molecular formula

Question 24

• Reflects the simplest ratio of atoms in the compound

Answer 24

Empirical formula

Question 25

METALS WITH IONS OF ___ CHARGE
Some representative elements and most transition elements can form more than one cation

EX: Copper chloride is ambiguous

Answer 25

more than one