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How do I figure out the relative reducing agent strengths of metals (including the transition metals) from the Databooklet?

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Hello, I am taking the Chemistry SL finals in less than two weeks and I ran into a odd question. This is the question:

 

Draw an annotated diagram of a voltaic cell composed of a magnesium electrode in 1.0 mol dm–3 magnesium nitrate solution and a silver electrode in 1.0 mol dm–3 silver nitrate solution. State the direction of electron flow on your diagram.

 

This is a paper two question and no reactivity series was provided. From the Databooklet, what diagram/chart/table can I use to figure out that magnesium is the stronger reducing agent compared to silver and hence undergoes oxidation at the anode (negative electrode)?

Or am I supposed to memorize the reactivity of magnesium compared to that of silver and other metals and transition metals? I was able to answer the question correctly because I sort of just remembered that magnesium is one of the strongest reducing agents, but I don't know any other of them.

 

P.s. I looked at table 14 on page 12 in the databooklet and there is obviously something going on here, but wth are standard electrode potentials and how do I read this table to my benefit. Haha I'm sort of freaking out right now XD 

Edited by maturk

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Hello, I am taking the Chemistry SL finals in less than two weeks and I ran into a odd question. This is the question:

 

Draw an annotated diagram of a voltaic cell composed of a magnesium electrode in 1.0 mol dm–3 magnesium nitrate solution and a silver electrode in 1.0 mol dm–3 silver nitrate solution. State the direction of electron flow on your diagram.

 

This is a paper two question and no reactivity series was provided. From the Databooklet, what diagram/chart/table can I use to figure out that magnesium is the stronger reducing agent compared to silver and hence undergoes oxidation at the anode (negative electrode)?

Or am I supposed to memorize the reactivity of magnesium compared to that of silver and other metals and transition metals? I was able to answer the question correctly because I sort of just remembered that magnesium is one of the strongest reducing agents, but I don't know any other of them.

 

P.s. I looked at table 14 on page 12 in the databooklet and there is obviously something going on here, but wth are standard electrode potentials and how do I read this table to my benefit. Haha I'm sort of freaking out right now XD

Well firstly, (obviously) you would draw a voltaic cell :P

You would then look at the positive and negative electrodes. Positive ions are attracted to the negative electrode and vice versa. Then, you should know which 1 out of the 2 ions available would exist and react by looking and analyzing the standard electrode potentials. Hope this helps! :)

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The more negative the standard electrode potential, the stronger the reducing agent. Magnesium has the more negative standard electrode potential therefore it will be oxidized (it will be the anode in the voltaic cell). Silver has has the more positive standard electrode potential therefore it will be reduced ( it will be the cathode in the voltaic cell). In a voltaic cell the electrons flow from the metal will the more negative value to the metal with the more positive value ( from magnesium to silver). Table 14 has the standard electrode potential values that you need.

Edited by Msj Chem
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Hello, I am taking the Chemistry SL finals in less than two weeks and I ran into a odd question. This is the question:

 

Draw an annotated diagram of a voltaic cell composed of a magnesium electrode in 1.0 mol dm–3 magnesium nitrate solution and a silver electrode in 1.0 mol dm–3 silver nitrate solution. State the direction of electron flow on your diagram.

 

This is a paper two question and no reactivity series was provided. From the Databooklet, what diagram/chart/table can I use to figure out that magnesium is the stronger reducing agent compared to silver and hence undergoes oxidation at the anode (negative electrode)?

Or am I supposed to memorize the reactivity of magnesium compared to that of silver and other metals and transition metals? I was able to answer the question correctly because I sort of just remembered that magnesium is one of the strongest reducing agents, but I don't know any other of them.

 

P.s. I looked at table 14 on page 12 in the databooklet and there is obviously something going on here, but wth are standard electrode potentials and how do I read this table to my benefit. Haha I'm sort of freaking out right now XD

Well firstly, (obviously) you would draw a voltaic cell :P

You would then look at the positive and negative electrodes. Positive ions are attracted to the negative electrode and vice versa. Then, you should know which 1 out of the 2 ions available would exist and react by looking and analyzing the standard electrode potentials. Hope this helps! :)

 

How would I go about analysing the electrode potentials? I'm in SL and to my knowledge the syllabus does not cover these "standard electrode potentials", for example those seen in table 14, so I have no idea what they are. In fact the syllabus clearly states that "standard electrode potentials will not be assessed" for SL students. Could you (or anyone else) give me a quick run down to what they are? Hm, this question is actually really weird and off topic for SL students because it looks like it requires some HL information. Weird :/ I suppose for SL I'll just have to know that magnesium is a stronger reducing agent.

 

Edit: Upon further analysis of the Chemistry SL syllabus I found that in 9.4.1 the teachers notes states that: "examples of half-cells are Mg, Zn, Fe and Cu in solutions of their ions." So I guess I do have to memorize the reactivity of said elements for voltaic cells. 

Edited by maturk

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The more negative the standard electrode potential, the stronger the reducing agent. Magnesium has the more negative standard electrode potential therefore it will be oxidized (it will be the anode in the voltaic cell). Silver has has the more positive standard electrode potential therefore it will be reduced ( it will be the cathode in the voltaic cell). In a voltaic cell the electrons flow from the metal will the more negative value to the metal with the more positive value ( from magnesium to silver). Table 14 has the standard electrode potential values that you need.

 

Wow thanks! So, all I need to know is "the more negative the standard electrode potential, the stronger the reducing agent." Thank you so much :)

 

I've noticed that the Databooklet has a lot of irrelevant stuff for SL students but they still help me out sometimes if I understand what they are haha XD The booklet is a lifesaver, I would die if we weren't allowed to use them in our finals. 

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