Daily Quiz

Daily Quiz1. What type of reaction is this?

Ca + Br2 → CaBr2

a. Synthesis

b. Decomposition

c. Combustion

d. Single replacement

e. Double replacement

Daily Quiz2. To be “happy,” an atom needs all of the following excepta.Equal numbers of + and - charges

b.Equal numbers of neutrons and protons

c.Electron shells are exactly full

Daily Quiz3. When calcium ionizes, its charge becomesa.+1

b.+2

c. -2

d. -1

e. 0

Daily Quiz4. When sodium gives an electron to chlorine, chlorine isa.oxidized

b.reduced

HINT: Remember the lion!

Today we will•Review the homework

•Look at the rules for determining oxidation number

HomeworkQuestions 1-3 on page 640

Homework1. Identify each of the following changes as either oxidation or reduction. Recall that e- is the symbol for an electron.

a.I2 + 2e- → 2I-

Homework1. Identify each of the following changes as either oxidation or reduction. Recall that e- is the symbol for an electron.

a.I2 + 2e- → 2I-

reduction

Homework1. Identify each of the following changes as either oxidation or reduction. Recall that e- is the symbol for an electron.

b. K → K+ + e-

Homework1. Identify each of the following changes as either oxidation or reduction. Recall that e- is the symbol for an electron.

b. K → K+ + e-

oxidation

Homework1. Identify each of the following changes as either oxidation or reduction. Recall that e- is the symbol for an electron.

c. Fe2+ → Fe3+ + e-

Homework1. Identify each of the following changes as either oxidation or reduction. Recall that e- is the symbol for an electron.

c. Fe2+ → Fe3+ + e-

oxidation

Homework1. Identify each of the following changes as either oxidation or reduction. Recall that e- is the symbol for an electron.

d. Ag+ + e- → Ag

Homework1. Identify each of the following changes as either oxidation or reduction. Recall that e- is the symbol for an electron.

d. Ag+ + e- → Agreduction

Homework2. Identify what is oxidized and what is reduced in the following processes.

a. 2Br- + Cl2 → Br2 + 2Cl-

Homework2. Identify what is oxidized and what is reduced in the following processes.

a. 2Br- + Cl2 → Br2 + 2Cl-

ox red

Homework2. Identify what is oxidized and what is reduced in the following processes.

b. 2Ce + 3Cu2+ → 3Cu + 2Ce3+

Homework2. Identify what is oxidized and what is reduced in the following processes.

b. 2Ce + 3Cu2+ → 3Cu + 2Ce3+

red ox

Homework2. Identify what is oxidized and what is reduced in the following processes.

c.2Zn + O2 → 2ZnO

Homework2. Identify what is oxidized and what is reduced in the following processes.

c.2Zn + O2 → 2ZnO

ox red

Homework3. Identify the oxidizing agent and the reducing agent in each of the following reactions.

a.Mg + I2 → Mg I2

Homework3. Identify the oxidizing agent and the reducing agent in each of the following reactions.

a. Mg + I2 → Mg I2

red ox

Homework3. Identify the oxidizing agent and the reducing agent in each of the following reactions.

b.2Na + 2H+ → 2Na+ + H2

Homework3. Identify the oxidizing agent and the reducing agent in each of the following reactions.

b. 2Na + 2H+ → 2Na+ + H2 red ox

Homework3. Identify the oxidizing agent and the reducing agent in each of the following reactions.

c.H2S + Cl2 → S + 2HCl

Homework3. Identify the oxidizing agent and the reducing agent in each of the following reactions.

c. H2S + Cl2 → S + 2HCl

red ox

Determining Oxidation Numbers

There are nine rules.You do not have to memorize them.But you do have to use them.

Determining Oxidation Numbers

KClO3

Determining Oxidation Numbers

KClO3

O is always -2 (rule 5)K is +1 (rule 7)The sum is zero (rule 8)

Determining Oxidation Numbers

KClO3NK + NCl + 3(NO) = 0

O is always -2 (rule 5)K is +1 (rule 7)The sum is zero (rule 8)

Determining Oxidation Numbers

KClO3 +1 + NCl + 3(-2) = 0

O is always -2 (rule 5)K is +1 (rule 7)The sum is zero (rule 8)

Determining Oxidation Numbers

KClO3NCl = +5

O is always -2 (rule 5)K is +1 (rule 7)The sum is zero (rule 8)

Determining Oxidation Numbers

SO32-

O is always -2 (rule 5)The sum is -2 (rule 9)

Determining Oxidation Numbers

SO32-

NS + 3(NO) = -2

O is always -2 (rule 5)The sum is -2 (rule 9)

Determining Oxidation Numbers

SO32-

NS - 6 = -2

O is always -2 (rule 5)The sum is -2 (rule 9)

Determining Oxidation Numbers

SO32-

NS = +4

O is always -2 (rule 5)The sum is -2 (rule 9)

Try a few on your own:

Due at the end of the period:Problems 4-9 on pages 642-643

Homework:Problems 10-11 on page 643