8.1 A nickel (Ni) rod is placed in a beaker containing a silver nitrate solution, AgNO3(aq) and a reaction takes place - NSC Physical Sciences - Question 8 - 2016 - Paper 2
Question 8
8.1 A nickel (Ni) rod is placed in a beaker containing a silver nitrate solution, AgNO3(aq) and a reaction takes place.
Write down the:
8.1.1 NAME or FORMULA of th... show full transcript
Worked Solution & Example Answer:8.1 A nickel (Ni) rod is placed in a beaker containing a silver nitrate solution, AgNO3(aq) and a reaction takes place - NSC Physical Sciences - Question 8 - 2016 - Paper 2
Step 1
8.1.1 NAME or FORMULA of the electrolyte
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Answer
The electrolyte in this reaction is silver nitrate, which can be written as AgNO₃.
Step 2
8.1.2 Oxidation half-reaction that takes place
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The oxidation half-reaction involves the nickel rod losing electrons:
ightarrow ext{Ni}^{2+} + 2e^-$$
Step 3
8.1.3 Balanced equation for the net (overall) redox reaction that takes place
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The overall redox reaction combines the oxidation of nickel and the reduction of silver ions:
ightarrow ext{Ni}^{2+} + 2 ext{Ag}$$
Step 4
8.2.1 Which electrode (Ni or Ag) must be connected to the negative terminal of the voltmeter? Give a reason for the answer.
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The nickel (Ni) electrode must be connected to the negative terminal of the voltmeter. This is because nickel is a stronger reducing agent than silver and loses electrons more readily, making it the anode and thus negative.
Step 5
8.2.2 Write down the cell notation for the galvanic cell.
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The cell notation for the galvanic cell including the nickel and silver half-cell can be written as:
ext{Ni(s)} igg| ext{Ni}^{2+}(aq) || ext{Ag}^+(aq) igg| ext{Ag(s)}
Step 6
8.2.3 Calculate the initial reading on the voltmeter if the cell functions under standard conditions.
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Under standard conditions, the cell potential is calculated using standard reduction potentials:
E°=Ereduction−Eoxidation=0.80extV−(−0.27extV)=1.07extV
Step 7
8.2.4 How will the voltmeter reading be affected if the concentration of the silver ions is increased?
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The voltmeter reading will INCREASE. This is because an increase in the concentration of the silver ions enhances the driving force for the reduction reaction, resulting in a higher cell potential.
