# Chem

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Manganese dioxide reacts with bromide ions to form manganese ions and bromate ions in an acidic aqueous solution. Write the balanced equation for this reaction.

1)Br- + MnO2 + 3H2O --> Mn2+ + BrO3- + 2H3O+

2)Br- + 3MnO2 + 6H3O+ ---> 3Mn2+ + 9H2O + BrO3-

3)6Br- + MnO2 + 48H2O ---> Mn2+ + 32H3O+ + 6BrO3-

4)4Br- + 3MnO2 + 18H2O ---> 3Mn2+ + 12H3O+ + 4BrO3-

5)Br- + 3MnO2 + 3H3O+ ---> 3Mn2+ + BrO3- + 3H2O

I got the first one. Is that right?

• Chem -

1)Br- + MnO2 + 3H2O Mn2+ + BrO3- + 2H3O+

2)Br- + 3MnO2 + 6H3O+ 3Mn2+ + 9H2O + BrO3-

3)6Br- + MnO2 + 48H2O Mn2+ + 32H3O+ + 6BrO3-

4)4Br- + 3MnO2 + 18H2O 3Mn2+ + 12H3O+ + 4BrO3-

5)Br- + 3MnO2 + 3H3O+ 3Mn2+ + BrO3- + 3H2O

I got the first one. Is that right?

• Chem -

Your equatioh isn' balanced. Furthermore, several students (you are one of them) don't use arrows. How can you tell which are reactants and which are products with no arrow?
(Charge doesn' balance. On left you have 1- and 2+ = 1+. On the right you have 2+, 1-, 2+ = 3+.