Redox Reactions

Question 1

oxidation state

Answer 1

value assigned to atom of compound, measures electron control or possession. The apparent chage that an atom has in a molecule or ion.

Question 2

Fluorine Oxidation State

Answer 2

-1

Question 3

Chlorine Oxidation State

Answer 3

-1

Question 4

Hydrogen Oxidation State

Answer 4

+1

Question 5

Oxygen Oxidation State

Answer 5

-2

Question 6

Exceptions to O, H, Cl, F oxidation states

Answer 6

when F, Cl, H, O are bonded to each other, the oxidation state stays the same

Question 7

What is the oxidation number of an element on its own?

Answer 7

0

Question 8

What is the oxidation number of a simple ion?

Answer 8

the charge of the ion

Question 9

What is the sum of oxidation state of a compound?

Answer 9

0

Question 10

What charge do metals have

Answer 10

positive

Question 11

In reduction what happens for ionic and covalent bonds?

Answer 11

• ionic bond- negative ion

- covalent bond- atom has higher electron density around it

Question 12

In oxidation what happens for ionic and covalent bonds?

Answer 12

• ionic bond- positive ion

- covalent bond- ion has lower electron density around it

Question 13

What are the exceptions to F having an oxidative state of -1?

Answer 13

F is always -1

Question 14

What are the exceptions of O have an oxidative state of -1?

Answer 14

• combining with H2, where it’s -1

- combining with F2, where it’s +2

Question 15

Li, Na, K Oxidation State

Answer 15

+1

Question 16

Mg, Ca Oxidation State

Answer 16

+2

Question 17

oxidizing agent

Answer 17

reactant that accepts electrons to become reduced, bringing about oxidation of other reactant

Question 18

reducing agent

Answer 18

reactant that supplies the electrons to become oxidized, bringing about reduction of other reactant

Question 19

Where are the electrons in the equation for oxidation?

Answer 19

right side/ product side

Question 20

Where are the electrons in the equations for reduction?

Answer 20

left side/ reactant side

Question 21

Which metals are stronger reducing agents? And why?

Answer 21

reactive metals, they have the tendency to lose electrons and will push their electrons on to other substances to form positive ion
- displace other substance

Question 22

What is the definition of an activity series?

Answer 22

to predict if a particular redox reaction between metal and ions of another metal will be feasible

Question 23

What are the products of the electrolysis of Brine?

Answer 23

• hydrogen gas
• chlorine gas
• sodium hydroxide

Question 24

What is 2 things hydrogen gas is used for?

Answer 24

• rocket fuel

- tracer isotope

Question 25

What are two things chlorine gas is used for?

Answer 25

- disinfectant | - treat swimming pool water

Question 26

What are 2 sodium hydroxide is used for?

Answer 26

- drain cleaner | - soaps/ detergent

Question 27

What is a redox reaction?

Answer 27

a reaction where 1 substance is reduced and the other is oxidized

Question 28

More reactive non-metals are stronger ______ agents.

Answer 28

stronger oxidizing agents, most readily reduced

Question 29

Differences between acid/base titration and redox titration

Answer 29

- AC titr. = neutralization between acid and base - RT= between oxidizing and reducing agent - AC titr= protons transferred from acid to base - RT= electrons transferred from reducing to oxidizing agent

Question 30

State what is oxidized and reduced in analysis of iron with manganate (VII)

Answer 30

- oxidized- Fe2+ to Fe3+ | - reduced- MnO4- to Mn2+

Question 31

In analysis of iron with manganate (VII) what is the color change?

Answer 31

purple to colourless

Question 32

What are redox titrations used for?

Answer 32

- pharmaceutical industry | - food and beverage industry

Question 33

In iodine-thiosulfate reaction, what is the visible color change?

Answer 33

deep blue to colourless

Question 34

In iodine-thiosulfate reaction, what is the indicator and when is it added

Answer 34

starch, and it is added during the titration

Question 35

In iodine-thiosulfate reaction, what is the oxidizing and reducing agent?

Answer 35

- oxidizing: iodine | - reducing: thiosulfate ion

Question 36

What is the BOD- biological oxygen demand?

Answer 36

- high BOD- low oxygen content in water | - low BOD- good oxygen content in water

Question 37

What precautions do you take in the Winkler method?

Answer 37

- when pouring water, funnel should touch flask so no extra oxygen in added from air

Question 38

What phosphates cause eutrophication and what does this do to oxygen?

Answer 38

- NO3- and PO43- cause algae blooms | decimating levels of O2

Question 39

How is dissolved oxygen fixed during the winkler method?

Answer 39

- by adding Mn2+ compound

Question 40

What compound is always added to the iodine in the winkler method, making it a titrations?

Answer 40

- iodine thiosulfate

Question 41

What are the two types of electrochemical cells?

Answer 41

voltaic (galvanic) and electrolytic

Question 42

How do voltaic cells generate electricity?

Answer 42

from spontaneous redox reactions which generate electricity`

Question 43

How do electrolytic cells generate electricity?

Answer 43

non-spontaneous redox reactions: drive chemical reactions using electricity

Question 44

What is a half cell?

Answer 44

a strip of metal in an electrolytic solution of its own ions

Question 45

What is the oxidation number for copper?

Answer 45

Cu2+

Question 46

What is the electrode potential?

Answer 46

the charge difference between the strip of metal and the solution of its own ions

Question 47

Term used to describe electrodes when they don't take part in redox reactions.

Answer 47

Inert

Question 48

In an electrolytic cell, where does oxidation take place?

Answer 48

anode (+), where anions are oxidized

Question 49

In an electrolytic cell, where does reduction take place?

Answer 49

cathode (-), where cations are reduced

Question 50

What is an electrolytic cell?

Answer 50

Cell that produces a non-spontaneous redox reaction driven by outside electricity

Question 51

What type of reaction is produced through an electrolytic cell?

Answer 51

endothermic reaction

Question 52

What type of reaction is produced through a voltaic cell?

Answer 52

exothermic reaction

Question 53

What is a voltaic/galvanic cell?

Answer 53

a spontaneous redox reaction that produces electricity

Question 54

What two connections must a voltaic cell have?

Answer 54

- external electronic circuit | - salt bridge to complete the circuit

Question 55

What does a salt bridge contain? Also, what does the salt bridge maintain?

Answer 55

an aqueous solution of ions | - maintains the potential difference

Question 56

Without a salt bridge, what happens to the voltage?

Answer 56

no voltage is generated

Question 57

How to test for hydrogen

Answer 57

squeaky pop

Question 58

How to test for chlorine

Answer 58

damp blue litmus paper turns red then white

Question 59

In all cells, electrons flow from ____ to _____.

Answer 59

In all cells, electrons flow from anode to cathode.

Question 60

Write equation for iron with manganate (VII)

Answer 60

DO IT

Question 61

Write 2 of the equations for the Iodine- thiosulfate reactions.

Answer 61

DO IT NOW