Initial observations: before beginning Observations Observations after 30 minute
ID: 1015625 • Letter: I
Question
Initial observations: before beginning Observations Observations after 30 minutes Chemical equation Element that is oxidized Element that is reduced Spectator ion Oxidizing agent Reducing agent www.HOLscience.com 16 ©Hands-On Labs, Inc. Experiment Oxidation-Reduction Activity Series Questions A. Define oxidation, reduction, and oxidation number. Describe how oxidation and reduction affect the oxidation number of an element. B. Define oxidizing agent, reducing agent, and spectator ion. C. In the reaction of copper and silver nitrate, a new substance appeared in the test tube. Describe the physical appearance of the substance and identify its chemical formula. D. Given an activity series in which the most active metals are at the top of the list and the least active metals are at the bottom of the list, would copper be listed above silver or would silver be listed above copper? Support your answer with data from Data Table 1. E. Solid copper sulfide and silver nitrate react to form copper (II) nitrate and solid silver sulfide. Write a balanced chemical equation that describes the reaction. Identify the oxidation number of each element in the reaction. (You do not need to include the total contribution of charge.) Is this reaction a redox reaction or a non-redox reaction? Explain your answer. www.HOLscience.com 17 ©Hands-On Labs, Inc. Experiment Oxidation-Reduction Activity Series Exercise 2: Creating an Activity Series Data Table 2. Redox Reactions of Copper, Lead, and Zinc Solid metal Well ID Solution Immediate observations 30 Minute Observations Cu A1 Pb(NO3 ) 2 A2 Zn(NO3 ) 2 Pb B1 CuSO4 B2 Zn(NO3 ) 2 Zn C1 CuSO4 C2 Pb(NO3 ) 2 Data Table 3. Potential Redox Reactions and Chemical Equations Metal and Metallic Solution Reaction Occurred? Chemical Equation Cu + Pb(NO3 ) 2 Cu + Zn(NO3 ) 2 Pb + CuSO4 Pb + Zn(NO3 ) 2 Zn + CuSO4 www.HOLscience.com 18 ©Hands-On Labs, Inc. Experiment Oxidation-Reduction Activity Series Zn + Pb(NO3 ) 2 Questions A. List each of the metals tested in Exercise 2. Indicate the oxidation number when each element is pure and the oxidation number when each element is in a compound. B. Which of the metals in Exercise 2 was the strongest oxidizing agent? Was there an instance when this metal also acted as a reducing agent? Explain your answer using data from Data Table 3. C. Which of the metals in Exercise 2 was the strongest reducing agent? Was there an instance when this metal also acted as an oxidizing agent? Explain your answer using data from Data Table 3. D. How does ease of oxidation correlate with activity? Do highly active metals tend to donate electrons or accept electrons from other metals? E. Create an activity series for copper, lead, and zinc. Place the most active metal at the top of the list.
Explanation / Answer
(A) Oxidation: The process that involved in the loss of electrons is called oxidation.
Reduction: The process that involved in the gain of electrons is called reduction.
Oxidation number: it is just simply as the charge of ion.
In oxidation process, the oxidation number of one of the elements is increased.
In reduction process, the oxidaton number of one of the elements is decreased.
(B) Oxidising agent: The species which oxidises other species (or) the species which undergoes in reduction.
Reducing agent : The species which reducues othe species (or) the species which undergeos in oxidation.
Spectator ions: The ions which does not undergo either oxidation or reduction.
(C) Cu(s) + AgNO3 (aq.) ----------> Cu(NO3)2 (aq.) + Ag (s)
the new substance obtained is Silver.
(D) Copper is active than silver, hence it is observed above silver in the activity series.
(E) CuS(aq.) + AgNO3 (aq.) ----------> Cu(NO3)2 (aq.) + Ag2S(s)
oxidation state of copper before and after the reaction is +2 and that of silver is +1. Hence it is not a redox reaction.
Excercise 2 :
(A) Zn, Pb, Cu
Oxidation number of each element in pure state is 'Zero' and that of in compound state is +2.
(B) Strong oxidising agent among the three metals is Cu.
It also acts as reducing agent when it reacts with the compounds of metals that lie below it like silver.
(C) Stongest reducing agent is Zn,
It can also acts as oxidising agent when its compounds reacts with metals that lie above it like Mg.
(D) Higly active metals tend to donate electrons than other metals. And thus they tend to undergo oxidation.
(E) Zn > Pb > Cu