Which of the following chemical reactions is an oxidation-reduction reaction?
A) CuSO4 + BaCl2 -- BaSO4 + CuCl2
B) Pb(NO3)2 + 2NaCl --- PbCl2 + 2NaNO3
C) N2 + 3H2 -- 2NH3
D) K2SO4 + BaCl2 --- BaSO4 + 2KCl

Question

Which of the following chemical reactions is an oxidation-reduction reaction? 
A) CuSO4 + BaCl2 -->  BaSO4 + CuCl2 
B) Pb(NO3)2 + 2NaCl  ---> PbCl2 + 2NaNO3 
C) N2 + 3H2 -->  2NH3 
D) K2SO4 + BaCl2 --->  BaSO4 + 2KCl

unklerhaukus · Answer

Compare the valentcy states of species on both sides of the equations

unklerhaukus · Answer

valency *

unklerhaukus · Answer

For A:    the copper has a valency of +2 on the left (as to match up with the SO_4^2-)
 and on the right it is also +2 (to match with the 2Cl-)

this means that the copper has not changed valence state

unklerhaukus · Answer

similarly, the barium in A   is +2 valence state on both sides

unklerhaukus · Answer

@chariety101, do you understand what i'm saying ?

anonymous · Answer

im not sure if i do... @UnkleRhaukus

caozeyuan · Answer

Harbor process is definitely redox

caozeyuan · Answer

Hence C

michele_laino · Answer

Please, you have to check in which reaction, there is a change of the oxidation number of the various substances