Oxidation
In which compound does chlorine have an oxidation number of +5?
(A) HClO
(B) HClO2
(C) HClO3
(D) HClO4
(C) HClO3
The reaction
CuO + CO --> CO2 + Cu
is an example of
(A) reduction, only
(B) oxidation, only
(C) both oxidation and reduction
(D) neither oxidation nor reduction
(C) both oxidation and reduction
Given the reaction:
F2(g) + 2 Br–(aq) → Br2(l) + 2 F–(aq)
Which species is reduced?
(A) F2(g) (C) Br2(l)
(B) Br–(aq) (D) F–(aq)
(A) F2(g)
What is the oxidation number of F in HF?
-1
This type of reaction is caused by a transfer of electrons, changing the oxidation number from reactants to products
oxidation reduction reaction
Given the redox reaction:
2 NiOOH + Cd → 2Ni(OH)2 + Cd(OH)2
Which species is oxidized?
(A) Cd
(B) Cd2+
(C) Ni(OH)3
(D) Ni(OH)2
(A) Cd
Is this a redox reaction?
OH– + H+ → H2O
no
Given the equation: 2 Al + 3 Cu2+ → 2 Al3+ + 3 Cu
Which element is reduced?
Cu
What is the oxidation number of H in NaH?
If something is oxidized, did that thing lose or gain electrons?
lose
Given the lead-acid battery reaction:
Pb + PbO2 + 2H2SO4 → 2 PbSO4 + 2 H2O
Which species is oxidized during battery discharge?
(A) Pb
(B) PbO
(C) SO4 2–
(D) H2O
(A) Pb
The transfer of which particle is required for a redox reaction to occur?
(A) electron
(B) ion
(C) neutron
(D) proton
(A) electron
Given the reaction: Ca(s) + Cu2+(aq) → Ca2+(aq) + Cu(s), which character is NOT reduced?
Ca
Which element ALWAYS has a -1 oxidation number no matter what?
F
What is the gain of electrons called in oxidation reduction reactions?
reduction
In which substance does chlorine have an oxidation number of +1?
(A) Cl2
(B) HCl
(C) HClO
(D) HClO2
(C) HClO
A redox reaction always involves
(A) a change in oxidation number
(B) a change of phase
(C) the transfer of protons
(D) the formation of ions
(A) a change in oxidation number
How do you know that Mg to Mg2+ is reduced?
It's not, it's oxidized
What is the oxidation number of P in PO4 3-
P = +5
Zn + Cu 2+ -> Zn 2+ + Cu
What is oxidized what is reduced?
Zn is oxidized, Cu is reduced
In which substance does sulfur have an oxidation state of +4?
(A) H2S
(B) S
(C) SO3
(D) SO2
(D) SO2
Which is a redox reaction?
(A) H+ + Cl– → HCl
(B) NaOH + HCl → NaCl + H2O
(C) Fe + 2 HCl → FeCl2 + H2
(D) MgO + H2SO4 → MgSO4 + H2O
(C) Fe + 2 HCl → FeCl2 + H2
H2 + O2 -> 2H2O
Which element is reduced?
O
What are all the rules we know about oxidation numbers
group 1 - +1
group 2 - +2
ion - charge of ion (Na+ - +1)
element by itself - 0
F - -1
O - -2
H - +1 with nonmetal, -1 with metal
Cl - mostly -1
What is the oxidation number for N in NO3-
N = +5