Hint 2.
Balance hydrogen by adding hydrogen ions
Given this partially balanced halfreaction
\(\rm 3H_2O+I^ \rightarrow IO_3{^}\)
how many \(\rm H^+\) ions should be added to the right side of the equation to balance hydrogen?
3
3
Express your answer numerically as an integer.
Hint 1.
Determine how many hydrogen atoms are on the left side of the equation
How many hydrogen atoms are currently shown on the left side of this equation?
\(\rm 3H_2O+I^ \rightarrow IO_3{^}\)
Express your answer numerically as an integer.
Hint 3.
Determine the number of electrons
How many electrons are needed on the more positive side of the equation to balance the charge?
\(\rm 3H_2O+I^ \rightarrow IO_3{^}\)
Express your answer numerically as an integer.
Part C
Use steps 3 and 4 listed in the introduction to rewrite this unbalanced halfreaction
\(\rm Cl_2 \rightarrow Cl{^}\)
such that it is balanced with respect to mass and charge. Do not include phases in your answer.
Express your answer as a chemical equation. Use the symbol
e

for an electron.
what coefficient should be placed in front of \(\rm Cl^\) to balance the chlorine atoms?
Express your answer numerically as an integer.
ANSWER:
3
3
Correct
Combining halfreactions
Since these halfreactions must occur together, the number of electrons lost in the oxidation halfreaction must equal the number gained in the reduction half
reaction. Make the number of electrons in both halfreactions equal by multiplying one or both halfreactions by a small whole number. Finally, sum the two half
reactions.
Part D
Given these balanced halfreactions
\(\rm 3H_2O+I^ \rightarrow IO_3{^}+6H^++6e^\)
\(\rm Cl_2+2e^ \rightarrow 2Cl^\)
enter the overall balanced redox reaction in an acidic solution. Do not include phases in your answer.
Enter your answer as a chemical equation.
Hint 1.
Balance the electron transfer
Given these halfreactions
\(\begin{array}{l}\rm A & \rm 3H_2O+I^ & \rightarrow & \rm IO_3{^}+6H^++6e^ \cr \rm B & \rm Cl_2+2e^ & \rightarrow & \rm 2Cl^ \end{array}\)
what must be done to balance the electron transfer?
ANSWER:
Hint 2.
How to add two reactions
If these two example reactions are added together
\(\begin{array}{l} \rm A & \rightarrow & \rm B+e^ \cr \rm X+e^ & \rightarrow & \rm Y \end{array}\)
the result is
\(\rm A+X+\cancel{\rm e^} \rightarrow \rm B+\cancel{\rm e^}+Y\)
where the cancelled electrons are omitted from the overall equation.
ANSWER:
Correct
Item 4
First
launch this video
. During the video, you’ll be asked a conceptual question about the example. After watching the video, answer the related questions at the
right. You can watch the video again at any point.
Part A