R-3 Redox Reactions Flashcards Preview

Wenger - AP Chemistry > R-3 Redox Reactions > Flashcards

Flashcards in R-3 Redox Reactions Deck (51):
1

What is the oxidation number of all of the atoms in the following species?

Ar

0

Note:  All elements have an oxidation number of 0

2

What is the oxidation number of all of the atoms in the following species?

CH4

C-4

H+1

Note:  Start with the hydrogen is +1 rule then use the compounds have a 0 oxidation number in order to determine the oxidation number of carbon.

3

What is the oxidation number of all of the atoms in the following species?

AlH3

Al+3

H-1

Note:  Metal hydrides are an exception to the hydrogen is +1 rule

4

What is the oxidation number of all of the atoms in the following species?

SiO2

Si+4

O-2

Note:  Start with the oxygen is -2 rule then use the compounds have an oxidation number of 0 rule in order to determine the oxidation number of silicon.

5

What is the oxidation number of all of the atoms in the following species?

OF2

O+2

F-1

Note: This is an exception to the O is -2 rule.

6

What is the oxidation number of all of the atoms in the following species?

H2

0

Note: All elements have an oxidation number of 0

7

What is the oxidation number of all of the atoms in the following species?

Fe3+

Fe+3

Note: All ions have an oxidation number equal to their charge.  When writing a charge the sign goes after the charge number (Fe3+).  When writing an oxidation number the sign goes before the charge number (Fe+3)

8

What is the oxidation number of all of the atoms in the following species?

N3-

N-3

Note: All ions have an oxidation number equal to their charge.  When writing a charge the sign goes after the charge number (N3-).  When writing an oxidation number the sign goes before the charge number  (N-3)

9

What is the oxidation number of all of the atoms in the following species?

AlN

Al+3

N-3

Note: All ions have an oxidation number equal to their charge. 

10

What is the oxidation number of all of the atoms in the following species?

Cu2S3

Cu+3

S-2

Note: All ions have an oxidation number equal to their charge and compounds have an oxidation number of 0.  Most transition metals can have multiple oxidation states so start with the sulfur (-2) so that you can infer the charge of the copper.  

11

What is the oxidation number of all of the atoms in the following species?

CaCO3

Ca+2

C+4

O-2

Note: All ions have an oxidation number equal to their charge (Ca+2), oxygen is -2 rule and compounds have an oxidation number of 0 will allow you to infer the oxidation number of the carbon atom.   

12

What is the oxidation number of all of the atoms in the following species?

Ni2(SO4)3

Ni+3

S+6

O-2

Note: All ions have an oxidation number equal to their charge so the oxidation number of the sulfate is -2.  Since oxygen is -2 the sulfur must be +6 to leave a -2 oxidation number for the sulfate.  Since all compounds have an oxidation number of 0 the nickle must be +3.   

13

What is the oxidation number of all of the atoms in the following species?

CaO2

Ca+2

O-1

Note: All ions have an oxidation number equal to their charge so the oxidation number of the calcium is +2.  The other ion is the peroxide ion and the oxygens in peroxide have an oxidation number of -1. 

14

What is the oxidation number of all of the atoms in the following species?

C2H5OH

C-2

O-2 

H+1

Note: The oxidation number of hydrogen is +1 and the oxidation number of oxygen is -2.  This means that the oxidation number of carbon must be -2 since the oxidation number of a compound must be a 0. 

15

What is the oxidation number of all of the atoms in the following species?

S8

0

Note: Sulfur is an element so the oxidation number is 0.

16

What is the oxidation number of all of the atoms in the following species?

NaN3

Na+1

N-1/3

Note: We will not see it too much but oxidation numbers can be fractional.

17

What is the oxidation number of all of the atoms in the following species?

NaN3

Na+1

N-1/3

Note: We will not see it too much but oxidation numbers can be fractional.

18

Is the following a redox reaction or not?

Na2O (s) + H2O (l) ⇒ 2 NaOH (aq)

Not

19

Is the following a redox reaction or not?

SO3 (g) + H2O (l) ⇒ H2SO4 (aq)

Not

20

Is the following a redox reaction or not?

Na2SO3 (aq) + 2 HCl (aq) ⇒ 2 NaCl (aq) + SO2 (g) + H2O (l)

Not

21

Is the following a redox reaction or not?

2 NaCl (aq) + F2 (g) ⇒ 2 NaF (aq) + Cl2 (g)

Redox

 

22

Is the following a redox reaction or not?

NaCl (aq) + Li (s) ⇒ Na (s) + LiCl (g)

Redox

 

23

Is the following a redox reaction or not?

Li2SO4 (aq) + Pb(NO3)2 (aq) ⇒ 2 LiNO3 + PbSO4 (s)

Not

 

24

Is the following a redox reaction or not?

C (s) + O2 (g) ⇒ CO2 (g)

Redox

25

Is the following a redox reaction or not?

2 CaO (s) ⇒ 2 Ca (s) + O2 (g)

Redox

 

26

Is the following a redox reaction or not?

2 C2H2 (g) + 5 O2 (g) ⇒ 4 CO2 (g) + 2 H2O (g)

Redox

 

27

Oxidation

Loss of electrons.  Results in an oxidation number that is more positive.

28

Loss of electrons.  Results in an oxidation number that is more positive.

Oxidation

29

Reduction 

Gain in electrons.  Results in an oxidation number that becomes more negative.

30

Gain in electrons.  Results in an oxidation number that becomes more negative.

Reduction 

31

Is the following an oxidation or a reduction half reaction?

Fe3+ + e- ⇒ Fe2+

Reduction

32

Is the following an oxidation or a reduction half reaction?

F2 + 2 e- ⇒ 2F-

Reduction

33

Is the following an oxidation or a reduction half reaction?

Cu ⇒ Cu+ + e- 

Oxidation

34

Is the following an oxidation or a reduction half reaction?

2 O2- ⇒ O2 + 4e- 

Oxidation

35

Is the following an oxidation or a reduction half reaction?

Cr2O72- + 14 H3O+ + 6 e- ⇒ 2 Cr3+ + 21 H2O

Reduction

36

Is the Fe atom in the following balanced redox reaction oxidized, reduced, both, or not changed?

Fe + 3 Ag+ ⇒ Fe3+ + 3 Ag

oxidized

37

Are the Ag+ ions in the following balanced redox reaction oxidized, reduced, both or not changed?

Fe + 3 Ag+ ⇒ Fe3+ + 3 Ag

Reduced

38

Are the Na atoms in the following balanced redox reaction oxidized, reduced, both or not changed?

2 Na (s) + 2 H2O (l) ⇒ 2 NaOH (aq) + H2 (g) 

oxidized - They go from 0 to +1.

39

Are the H atoms in the following balanced redox reaction oxidized, reduced, both or not changed?

2 Na (s) + 2 H2O (l) ⇒ 2 NaOH (aq) + H2 (g) 

2 are reduced (they go from +1 to 0) and 2 are unchanged (they stay at +1)

40

Are the O atoms in the following balanced redox reaction oxidized, reduced, both or not changed?

2 Na (s) + 2 H2O (l) ⇒ 2 NaOH (aq) + H2 (g) 

Unchanged (they stay at -2)

41

Are the H atoms in the following balanced redox reaction oxidized, reduced, both or not changed?

2 H2O2 (aq) ⇒ 2 H2O (g) + O2 (g)

Unchanged (they stay at +1)

42

Are the O atoms in the following balanced redox reaction oxidized, reduced, both or not changed?

2 H2O2 (aq) ⇒ 2 H2O (g) + O2 (g)

both (two of them go from -1 to -2 and two of them go from -1 to 0)

43

How many electrons are transfered in the following redox reaction?

Fe + 3 Ag+ ⇒ Fe3+ + 3 Ag

3 electrons are transfered from the Iron atom to the 3 silver ions

44

How many electrons are transfered in the following redox reaction?

2 Na (s) + 2 H2O (l) ⇒ 2 NaOH (aq) + H2 (g) 

2 electrons are transfered from the sodium atoms to two of the hydrogen atoms in the water molecules.

45

How many electrons are transfered in the following redox reaction?

2 H2O2 (aq) ⇒ 2 H2O (g) + O2 (g)

2 electrons are transfered.  One peroxide oxygen transfers an electron to the other so you get 0 and -2 oxidation numbers.  There are two peroxide molecules present so a total of 2 electrons are transfered.  This is a tough one.

46

What is the oxidizing agent in the following redox reaction?

Fe + 3 Ag+ ⇒ Fe3+ + 3 Ag

Silver ions

47

What is the reducing agent in the following redox reaction?

Fe + 3 Ag+ ⇒ Fe3+ + 3 Ag

Iron atoms

48

What is the oxidizing agent in the following redox reaction?

2 Na (s) + 2 H2O (l) ⇒ 2 NaOH (aq) + H2 (g) 

H2O (l)  is the oxidizing agent because it contains the hydrogen atoms that are reduced

49

What is the reducing agent in the following redox reaction?

2 Na (s) + 2 H2O (l) ⇒ 2 NaOH (aq) + H2 (g) 

Na (s)  is the reducing agent because it contains the sodium atoms that are reduced

50

What is the reducing agent in the following redox reaction?

2 H2O2 (aq) ⇒ 2 H2O (g) + O2 (g)

H2O2 is the reducing agent since it contains the O atom that is oxidized (goes from -1 to 0)

51

What is the oxidizing agent in the following redox reaction?

2 H2O2 (aq) ⇒ 2 H2O (g) + O2 (g)

H2O2 is the oxidizing agent since it contains the O atom that is reduced (goes from -1 to -2)