What redox reaction occurs between #MnO_2# and #HCl#?

1 Answer
Aug 6, 2017

Try........

#MnO_2(s) + 4H^(+) +2Cl^(-) rarr Mn^(2+) + 2H_2O(l)+Cl_2(g) #

Explanation:

Manganese oxide is reduced to colourless #Mn^(2+)#:

#MnO_2(s) + 4H^(+) + 2e^(-) rarr Mn^(2+) + 2H_2O(l)# #(i)#

Chloride ion is oxidized to #Cl_2# gas:

#Cl^(-) rarr 1/2Cl_2(g) + e^(-)# #(ii)#

And so we add the equations together in a way such that the electrons are cancelled: #(i) + 2xx(ii)# gives........

#MnO_2(s) + 4H^(+) +2Cl^(-) rarr Mn^(2+) + 2H_2O(l)+Cl_2(g) #

Alternatively.........

#MnO_2(s) + 2H^(+) +2HCl(aq) rarr Mn^(2+) + Cl_2(g) +2H_2O(l)#

or.............

#MnO_2(s) + 4HCl(aq) rarr MnCl_2(aq) + Cl_2(g) +2H_2O(l)#