Unit 4 Flashcards
(24 cards)
What is the difference in writing a charge and an oxidation state?
Oxidation state- +1
Charge- 1+
What is the oxidation state of fluorine always?
-1
What is the oxidation state of hydrogen when it’s bonded to a more electronegative element? A metal?
More electronegative- +1
Metal- -1
What is the difference between oxidation and reduction reactions? What’s LEO GER mean?
Oxidation- reaction where an ion or atom increases its oxidation state
Reduction- reaction where an ion or atom decreases its oxidation state
LEO- loss of electrons= oxidation
GER- gain of electrons= reduction
How does the number of electrons lost in an oxidation compare with the number gained in the simultaneous reduction?
The two number are equal
In redox reactions, which agent is the one being reduced? The oxidizing agent or reducing agent?
Oxidizing agent
What is a redox reaction?
A reaction where any oxidation numbers change
Ex: it is not a redox reaction if all the oxidation numbers are the same throughout
How do we balance redox reactions in acidic conditions?
Start off normal then if the H and O don’t balance you balance the O’s first by adding H2O’s to the side with less O’s. Then add H+ to the side needed to balance H
How do you balance redox reactions in basic conditions?
Balance the equation like acidic condition, then if you used an H+ you add an OH- to both sides equal to the amount of H+’s you used
What determines the strength of oxidizing and reducing agents?
Their abilities to give and take electrons
How easily
How does the strength of oxidizing/reducing agents table work in terms of order?
For example, any reducing agent can be oxidized by the oxidizer below it
Any oxidizing agent can be reduced by the reducer below it
What are the products when hydrogen peroxide decomposes?
Oxygen and water
What is a voltaic electrochemical cell?
Also called a galvanic cell that spontaneously converts chemically stored potential energy into moving electrons through a redox reaction
Example of voltaic cells?
Battery
What is produced when reactants in spontaneous energy releasing redox reactions are in direct contact? (Voltaic Cells)
Heat
What is red cat and an ox mean?
Red cat= reduction-cathode
An ox= oxidation-anode
What are electrolytic cells? Examples?
Cells where electricity is used to reverse a spontaneous redox process
It’s non spontaneous
Ex: recharging battery or electroplating
What is a voltaic wet cell?
The two beakers diagram with the salt bridge and the two electrodes in the beakers
What is the voltage of a voltaic cell by the E0 values determined by?
Half reactions of the cathode and anode
What is electroplating?
Normally a voltaic cell disappears an anode and grow the cathode but electroplating reverses this by changing the anode to a cathode
What is the object plated to in an electroplating cell?
Cathode
What is the electrode potential equation?
E^o cell= E^o cathode - E^o anode
What does the values of E^o have to be for a reaction to be either spontaneous or not spontaneous?
Spontaneous- E^o cell is positive
Not spontaneous- E^o cell is negative
How can we use the table of standard reduction potentials to find which elements in an equation are oxidized or reduced?
More positive potential on chart means it’s a cathode which means it’s reduced.
More negative potential on chart means it’s a anode which means it’s oxidized
