Skip to main content
Ch.19 - Electrochemistry
Chapter 19, Problem 150a

Chlorine can be prepared in the laboratory by the reaction of hydrochloric acid and potassium permanganate. (a) Use data in Appendix D to write a balanced equation for the reaction. The reduction product is Mn2+.

Verified step by step guidance
1
Identify the reactants and products: Hydrochloric acid (HCl) and potassium permanganate (KMnO4) react to produce chlorine gas (Cl2), manganese(II) ions (Mn2+), and other products.
Write the unbalanced chemical equation: \( \text{HCl} + \text{KMnO}_4 \rightarrow \text{Cl}_2 + \text{Mn}^{2+} + \text{KCl} + \text{H}_2\text{O} \).
Balance the atoms in the equation starting with the manganese (Mn) atoms: Ensure that the number of Mn atoms on both sides of the equation is equal.
Balance the chlorine (Cl) atoms: Since Cl appears in both HCl and Cl2, adjust the coefficients to balance the Cl atoms.
Balance the remaining atoms (H, O, and K) by adjusting the coefficients of HCl, H2O, and KCl, ensuring that the number of each type of atom is equal on both sides of the equation.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
6m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Balancing Chemical Equations

Balancing chemical equations involves ensuring that the number of atoms for each element is the same on both sides of the equation. This is based on the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. To balance an equation, coefficients are adjusted in front of the chemical formulas to achieve equal atom counts.
Recommended video:
Guided course
01:32
Balancing Chemical Equations

Redox Reactions

Redox reactions, or reduction-oxidation reactions, involve the transfer of electrons between species. In these reactions, one substance is oxidized (loses electrons) while another is reduced (gains electrons). Understanding the oxidation states of the elements involved is crucial for identifying which species undergo reduction and oxidation during the reaction.
Recommended video:
Guided course
03:12
Identifying Redox Reactions

Oxidation States

Oxidation states (or oxidation numbers) are assigned to atoms in a compound to indicate their degree of oxidation or reduction. They help in tracking electron transfer in redox reactions. For example, in the reaction between hydrochloric acid and potassium permanganate, the manganese in permanganate is reduced from an oxidation state of +7 to +2, indicating a gain of electrons.
Recommended video:
Guided course
02:42
Oxidation Numbers