module 14 electrolysis

SMK DATO BENTARA LUAR BATU PAHAT

MODULE 8: Periodic Table

Exercise1: Group 1. Elements lithium sodium potassium rubidium

Atom No3111927

Table above shows a list of proton number of Group 1 element in the periodic table, using the information above, answer this question.

a. Write the electron arrangement of lithium, sodium and potassium.

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b. State the electron valence of elements in group 1.

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c. Potassium atom will react to form potassium ion.

(i) Draw a diagrammatic atomic structure of potassium ion.

(ii) Write the electron arrangement of potassium ion.

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(iii) Write the ionic equation of the formation of potassium ion from potassium atom.

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d. Cesium is the element placed right after rubidium.

(i) State the valence electron of cesium.

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(ii) How does the reactivity of cesium compare to the rest of elements in group 1.

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(iii) The symbol of cesium is Cs, write the formula of Cesium oxide.

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e. (i) State the changes of atomic size of elements down group 1.

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(ii) Explain your answer.

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f. (i) State the changes of melting an boiling point of elements down group 1.

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g. (i) State the changes of melting point and boiling point of elements down group 1.

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h. Elements of group 1 react with water when a small piece of its metal are placed in

a container filled with water.

(i) State two observations when lithium and water react.

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(ii) Write a chemical equation of this reaction.

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(iii) Arrange the reactivity of lithium, sodium and potassium with water in an increasing order.

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(iv) Explain the reactivity in question (h) (iii).

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(v) Elements in group 1 are kept in paraffin oil in a laboratory. Explain why?

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i. Sodium burnt in oxygen to produced sodium oxide.

(i) Write the chemical equation for this reaction.

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(ii) State the observations while doing the experiment.

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j. Elements in group 1 react with chlorine gas in a laboratory.

(i) Draw a diagram to shows how this experiment can be done in a laboratory.

(ii) State any observations while doing the experiment.

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(iii) Write a chemical equation when potassium reacts with chlorine gas.

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Exercise 2: Group 17.ElementFClBrI

Atomic Number________________________

Electron arrangement____________--

a. Fill the table above by writing the atomic number and electron arrangement for fluorine

and chlorine in space provided.

(i) Draw the diagrammatic electron arrangement of fluoride ion.

(ii) Write the half equation of the reaction of fluorine atom to fluoride ion.

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b. Given that the nucleon number of bromine is 80.

Find the proton and neutron number of bromine atom.

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c. State the number of valence electron in bromine atom.

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d. If the formulae of bromide ion is Br , state the number of electron in bromide ion.

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(i) State the changes of atomic size of halogen atom down group 17.

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(iii) This elements exists naturally as molecule, give the physical state of this

molecule fluorine, chlorine, bromine and iodine.

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(iv) Explain why the physical state of these elements changes down group 17.

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e. Chlorine will react with iron wool if its heated in a laboratory.

(i) Draw a set of apparatus to show how the experiment is carry out in this reaction.

(ii) Write a chemical equation of this reaction.

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(iii) If 5.6 g of iron are heated with chlorine gas, find the mass of iron (III) chloride

produced.

[Relatifve atomic mass: Fe, 56; Cl, 35.5] [answer:16.25 g]

f. Glowing sodium will react with chlorine gas in a gas jar. .

(i) Write an equation of this reaction.

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(ii) State an observation when doing this experiment.

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(iii) 9.2 g of sodium are burnt in chlorine gas at room temperature.

Find the volume of chlorine gas used in this reaction.

[Relative atomic mass: Na, 23; Molar Volume of gas = 24 dm3 mol-1 at room

temperature]

MODULE 10: Chemical Bonding 1Answer all question.

1.

ElementProton NumberElectron numberNeutron number

X

Y

Z6

11

176

11

176

12

20

Answer question below by using the symbol given as in the table.

(a) Write the electron arrangement of Z atom.

(b) Y can react with Z to produce a compound.

(i) Give the formulae for this compound.

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(ii) What is the type of bond in this compound?

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(iii) What is you prediction of the physical state of this compound in room temperature? Explain you answer.

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(iv) Draw a diagrammatic electron arrangement to show the formation of

compound (b)

(c) X can react with oxygen to produced X oxide.

(i) Write this oxide X formulae.

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(ii) Give one physical properties of this oxide.

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(iii) Calculate the relative molecular mass for X oxide.

[Relative atomic mass: O, 16]

(d) Y can react with oxygen to produce another Y oxide.

(i) Draw a diagrammatic electron arrangement to show the formation of Y oxide.

(ii) Y oxide can react with water. Write a balance chemical equation to show this reaction.

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(e) Sodium can burnt in a chlorine gas to produced sodium chloride as in chemical equation below.

2Na + Cl2 ( 2NaCl

(i) If 5.75 g of sodium burnt in chlorine gas, what is the mass of sodium chloride formed?

[Nucleon number: Na, 23, Cl, 35.5, 1 mole gas occupies 24 dm3 at room temperature]

Answer: 14.625 g

(ii) What is the volume of chlorine gas that will react with sodium?

Answer: 3 dm3


1. Table below show the number of atom of 8 elements with the symbols of P, Q, R, S, T, U, V and W. Answer the questions by using the symbol provided.

ElementsPQRSTUVW

Proton number1112131415161718

(a) State the electron arrangement of elements Q and S.

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(b) State the number of period for elements T, hence explain why.

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(c) List down three elements which are metal.

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(d) State the electro negativity across this period.

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(e) Elements W is not reactive chemically, explain why.

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(f) (i) State the changing of atomic size across this period.

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________________________________________________________________

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(g) Draw a diagrammatic electron arrangement in

(i) P atom

(ii) P ion

(h) Elements P can react with elements V in lab.

(i) Write the balance chemical equation of the reaction of P with V.

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(ii) If 2.3g of P react with excess V gas, calculate the mass of compound produced.

[Nucleon number: P, 23; V, 35.5]

(i) R can react with oxygen to produced R oxide compound.

(i) Write R oxide formulae produced.

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(ii) What is the name given to R oxide?

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(iii) State the physical state of R oxide compound in room temperature.

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(iv) Explain why in question (iii).

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1.

ElementsEFGHIJKL

Proton No1112131415161718

Using the symbols given answer the question below.

(a) Write the electron arrangement for:

(i) E (ii) J2 - (iii) F2 +

(b) Elements F and K if combined will produce a compound.

(i) State the compound formulae formed .

(ii) Draw a diagrammatic electron arrangement of the compound formed.

(iii) Give the name of forces of attraction between the particles F with K.

.

(c) Element H and K react to produce a compound.

(i) Name the bond exist between particle H and K

.

(ii) State one properties of the compound formed.

.

Explain the properties of compound in (c) (ii)

.

.

(iii) Draw a diagrammatic electron arrangement of this compound.

(d) Elements G cannot react with L. Explain why.

.

(e) E will react with element K in lab. Write a balance chemical equation happen when E and K react.

.

(f) G reacts with oxygen to produced G oxide. Write these compound formulae.

.

2.Referring to the diagram, answer the question.

[Atom number Mg = 12, Cl = 17;

relative atomic mass Mg = 24, Cl = 35.5, NA = 6 x 1023 ]

(a) Write a electron arrangement of magnesium ion and chlorine atom.

(b) (i) Magnesium is placed in which period.

...


.

(c) (i) Write a formula of the compound formed from the ions above.

.

(ii) What is the type of bond formed?

.

(iii) State the properties of compound from (c) (i).

(iv) Explain the properties in question (c) (iii).

.

(d) Draw a diagrammatic electron structure of compound (c) (i).

(e) Write a half equation of transformation of

(i) Magnesium atom to magnesium ion.:

(ii) Chlorine molecule to chloride ion.: ...

(f) Find the number of molecule exist in 3.8 g magnesium chloride.

(g) Calculate the number of ion in 3.8 g magnesium chloride.

3.

A structured of hydrocarbon molecule is shown as above.

3. (a) State the type of bond exist in the above molecule.

(b) How does the molecule bond formed?

..

(c) (i) What is the forces exist in hydrocarbon molecule above.

.

(ii) Does the molecule above conduct electricity? Explain why?

(d) Hydrocarbon molecule burnt in excess oxygen to produced carbon dioxide and

water. Write a balance chemical equation to represent this reaction.

.

(e) (i) How many electrons is there in this molecule?

..

(ii) How many chemical bonds formed between carbon atoms with the other

carbon atom?

.

4.

SHAPE \* MERGEFORMAT

Figure above shows a diagrammatic electron arrangement of compound formed from elements X and Y.

(a) From the figure shown write the compound formula.

(b) What is the type of compound drawn above?

..

(c) Write the electron arrangement

(i) X atom

(ii) Y atom

.. .

(d) Do you expect that the melting point and freezing point of this compound is high or low? Explain your answer.

(e) Write the half equation of the formation of X ion from X atom.

..

(f) What is the name of the bond exist between ions in this compound.

..

(g) Name one compound that can be indicated by this example.

(h) From the electron point of view, explain how the bond was formed

.

MODULE 13: Periodic Table and Chemical BondingAnswer all question.

Periodic Table 1

1.

12131415161718

EG

JLMQ

R

T

Periodic Table above shows the position of eight elements which can be represent by the symbol of E, G, J, L, M, Q, R and T. Based on the symbol of this elements, answer the following questions.

(a) Give the other name for Group 2. : ..

(b) There are four metals and three non-metals in the periodic table. List these elements.

Metal: .Non-Metal : :

(c) Which of the elements in the periodic table above has the biggest radius?

(d) (i) Between elements T and J which one is more reactive?

(ii) Explain why.

(e) Write an ionic formula formed from elements

(i) R: (ii) L : .

(f) Write an electron arrangement of G atom.

(g) E can react with Q to produce a compound.

(i) What is the type of chemical bond exist in this compound?

(ii) Draw a diagrammatic electron arrangement in this compound of question

(g) (i).

(h) J reacts with Q to produce a compound. Draw a diagrammatic electron arrangement for this compound.

(i) Write a balance chemical equation that happens with R and molecule Q.

(j) A reaction of magnesium with chlorine can be represented by a chemical equation below.

2K + Cl2 ( 2KCl

If 3.9 g of potassium is burnt completely in chlorine gas, find the volume of chlorine reacts in this experiment.

[Chlorine gas: K, 39; 1 mol of gas occupies 24 dm3 at room temperature]

Answer: 1.2 dm3

MODULE 14: Electrochemical Electrolysis CellFactors that influence the ions that is to be discharged during electrolysis.

1. The position of ions in the Electrochemical Series, ES

2. If there is a competition for the following ions, ions with high concentration will be discharge.

Example : If (a) F- and OH-

(b) Br- and OH-

(c) I- and OH-Ions with high concentration (F-, Br- and I-) will be discharged during electrolysis.

3. If a non standard electrode is used in electrolysis, the electrode will erode.

Example of standard electrode is carbon (graphite) and platinum.

Example of non standard electrode is silver, copper and nickel.

Cu ( Cu2+ + 2e

Ag ( Ag+ + e

Ni ( Ni2+ + 2e

Answer all question.1. Electrolysis of silver nitrate solution is conducted for a few minutes in a lab and the observation is recorded.

(a) List the three factors that will determine ions that are selected to be discharged during electrolysis.

(b) State two observations of this experiment.

(c) Carbon electrode X and Y are labeled as in figure above, state which one is the cathode and anode.

(d) Write half equations of the reaction at cathode and anode.

Anode

:

Cathode:(e) State the changing of the form of energy in this experiment.

(f) What will happen to the concentration of silver ion, Ag+ if the experiment is conducted for a few minutes? Explain why.

(g) A gas is released at one of the carbon electrode.

(i)Name the gas.

(ii)Describe how you can recognize the gas.2. Electrolysis of copper (II) sulphate is conducted in laboratory with copper electrode for a few minutes and the observations of this experiment are recorded.

(a) If copper (II) sulphate solution is replaced with a solid copper (II) sulphate, can the experiment be done? Explain why.

(b) Write a half equation of the reaction at cathode and anode.

Anode

:

Cathode:(c) State the observation at cathode and anode.

Anode

:

Cathode:(d) What is the colour of copper (ii) sulphate?

(e) (i) Is there any changes of the colour of copper (II) sulphate after the experiment is conducted for a few hours?

(ii) The copper (II) ions are being discharged at cathode during electrolysis. Is there any difference in the concentration of copper (II) ions during the experiment?

(iii) Explain why.

(f) Name the product that is produced at cathode and anode

(i) Cathode

(ii) Anode

(g) If the copper anode is replaced with a carbon anode, what will you predict happen at anode?3. Electrolysis of concentrated copper (II) chloride solution 0.5 mole dm 3 is conducted in lab for a few hours.

(a) Write all ions exist in copper (II) chloride solution.

(b) (i) Write the half equation of the reaction happened at anode.

(ii) State the observation at anode.

(iii) Name the product that is produced at anode.

(c) (i) State the observations at cathode.

(ii) Write the half equation happened at cathode.

(iii) Explain the process that happened at cathode during electrolysis4. Electrolysis of hydrochloric acid 2 mol dm-3 is conducted in lab at school. The electrolysis is left for a few minutes before the observations are recorded.

(a) Draw a diagram to show how this electrolysis is done in lab. In your answer show how the gases are collected.

(b) Write all anions exist in the electrolyte.

(c) (i) Name the gas released at cathode.

(ii) State how the gas can be identified in lab.

(d) (i) Write the half equation of the reaction happened at anode.

(ii) State what happen if a litmus paper is placed near the gas.

(iii) The anions discharged during electrolysis at anode is based on one factor. State the factor.

(e) If the acid is replaced with a more dilute acid, which is 0.01 M. What is the anion that is selected to be discharged at anode during electrolysis?

5Diagram below shows two electrolytic cells.

(a)Electricity is passed through Cell I and II. Based on observation state the corresponding inferences.

ObservationInferenceColourless bubbles at anode Cell ICathode become thicker in Cell IAnode become thinner in Cell IIBlue solutions become paler in Cell IBlue solutions remain unchange in Cell II

(b)(i)After 10 minutes;

In Cell A, the colour of the solution changes from dark blue to light blue. In Cell B, there is no change of colour in the solution. Explain the difference.

Cell A: Cell B:

(ii)After 10 minutes, state how the colour of copper(II) sulphate solution changes in Cell A when the electrolysis process is keep proceed.

(c)Based on this experiment, what is the meaning of electrolysis?

(d)Draw a labelled diagram to show the electroplating of a iron ring with silver, using silver nitrate solution as the electrolyte.

(d)Classify all the ions that exist in copper(II) sulphate solution into cations and anions.

MODULE 15: Electrochemical Voltaic Cell

Answer all question.

1. A voltaic cell is constructed by dipping a magnesium ribbon and a lead strip in a M electrolyte in a beaker as shown below. The experiment is left for a few minutes and the result is recorded.

(a) Suggest an electrolyte that can be used in this experiment.

(b) State the observation in this experiment.

(c) Explain why the magnesium ribbon is eroded in this experiment.

(d) Write a half equation of the reaction both magnesium ribbon and lead strip.

(e) Write the overall ionic equation of this experiment.

(f) What happen to the concentration of lead (II) ion, Pb2+ after doing the experiment for a few minutes? Explain why.

(g) What do you predict happen to the voltmeter reading if both electrodes are placed nearer to each other in the ECS?

(h) At the figure above, mark the negative and positive terminal.

(i) State the movement of electrons in the experiment.

(j) Lead strip is replaced with another metal strip which will produce a higher voltage reading. Suggest the name for that metal strip.

(k) Lead strip is replaced with another metal strip which will produce a lower voltage reading. Suggest the name for that metal strip.

2. A voltaic cell experiment has been set up in a laboratory as figure below for at least 30 minutes. The observation and the reading of the ammeter is recorded.

(a) Name the voltaic cell.

(b) What is the purpose of using the ammeter in this experiment?

(c) What is the function of using the porous pot in this experiment

(d) State which is the

(i) Negative terminal

(ii) positive terminal

(e) State three observations while doing this experiment.

(f) What will happen to the concentration of copper (II), Cu2+ after doing the experiment for 30 minute. Explain why?

(g) Write a half equation of the reaction happened at both terminal.

(i) Negative terminal

(ii) Positive terminal

(h) Write an overall ionic equation of the reaction happen in the voltaic cell.

(i) State the changing of the form of energy in this cell.

(j) How do you know that the reaction in voltaic cell had just begun?

(k) If the zinc and zinc sulphate aqueous is replaced with magnesium ribbon and magnesium sulphate aqueous in other experiment.

(i) State the difference in reading of the ammeter.

(ii) Explain the difference in the reading.

3, A pupil wanted to construct the electrochemical series. He measured the potential difference of a few pairs of metals. The result obtained from the experiment after 30 minutes SHAPE \* MERGEFORMAT

(a) Describe the change to the electrodes after 30 minutes

(b) Predict the change that you would see in the copper(II) sulphate solution during the experiment.

(c) The experiment is repeated by substituting the zinc metal with iron, magnesium and lead.

diagram below shows the reading of the voltmeter.

SHAPE \* MERGEFORMAT

(d) For this experiment, state;

Manipulated variable.

Responding variable..

Fixed variable.

.(e) Record the voltmeter readings

Pairs of metalReading of voltmeter /V

Negative terminalPositive terminal

Zinc Copper

Iron Copper

MagnesiumCopper

Lead Copper

(f) State hypothesis for this experiment.MODULE 16: Acids and Bases

Titration of Acid and Base

1. 20.0 cm3 of dilute sulphuric acid 0.2 M is pour inside a conical flask. Add a few drops of universal indicator to the solution. Then add potassium hydroxides slowly into the conical flask. 15.0 cm3 of potassium hydroxide solution needed to exactly neutralise the sulphuric acid.

(a) Draw a labeled figure to shows the apparatus used in this titration experiment.

(b) Name an apparatus used to measure exactly 20.0 cm3 of dilute sulphuric acid 0.2 M.

(c) Reactions happen in the conical flask between sulphuric acid and potassium hydroxide solution.

(i) Name this reaction.

(ii) Write a balance chemical equation of the reaction.

(iii) Write an ionic equation for this reaction.

(d) State the changes of color of the solution inside the conical flask when it reaches the end point.

(e) How can you determine that the alkaline added to the acid is already excessive?

(f) (i) Calculate the number of mole for the sulphuric acid.

(ii) Calculate the concentration of potassium hydroxide in mol dm-3 used in this experiment.

2. An experiment is conducted to determine the concentration of sulfuric acid using the titration with sodium hydroxide solution 0.5 mol dm-3. Pour sodium hydroxide solutions inside a burette and sulfuric acid of 25 cm3 are poured inside a conical flask. 3 drops of universal indicator are added to the conical flask. Titration is started by taking the reading of the burette. Small quantities of sodium hydroxide are added until there is a changing of color in the conical flask. Repeat the experiment for three times and the readings are recorded as in table below.

ExperimentEarly Readings / cm3End Readings / cm3Volume of sodium hydroxide / cm3

10.012.3

212.525.0

325.037.4

(a) Give the definition of weak acid and give one example

(b) Name this reaction.

(c) Give one chemical properties of acid other than the reaction in question (b).

(d) Name an apparatus used to measure exact volume of sulfuric acid.

(e) State the changing of color in the conical flask while doing the experiment.

(f) Write the chemical equation for this reaction.

(g) Draw a figure to shows apparatus used in this experiment.

(h) (i) Fill the table above and find the average volume of sodium hydroxide used.

(ii) Find the number of mole for sodium hydroxide.

(iii) From question (h) (ii), calculate the concentration of sulfuric acid used.

(i) Why does the conical flask always have to be shaking while doing the experiment?

(j) Dilute sulfuric acid are pour inside a test tube and add 8 g of calcium carbonate to the test tube. Pass the gas released through another test tube fill with limewater.

[Relative atomic mass; Ca, 40; C, 12; O, 16; 1 mole of gas occupies 24 dm3 at room temperature]

(i) Draw a figure to shows an apparatus used in the experiment.

(ii) State two observations while doing the experiment.

(iii) Write a balance chemical equation for this reaction.

(iv) Find the volume of gas released at room temperature in this experiment.

Cl -

Mg2+

H

H

H

C

C

H

X

2 +

Y

_

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Transition Elements

K+

Na+

Ca2+

Mg2+

Al3+

Zn2+

Fe2+

Sn2+

Pb2+

H+

Cu2+

Ag+

Ion that is placed below in the ES is easier to be discharged during electrolysis

F-

SO42-

NO3-

Cl-

Br-

I-

OH-

Ion that is placed below in the ES is easier to be discharged during electrolysis

A

Silver nitrate aqueous

Rheostat

Carbon electrode Y

Carbon electrode X

Switch

Copper (II) sulphate solution

Copper electrode

Copper electrode

A

Copper (II) chloride aqueous

Rheostat

Carbon electrode Q

Carbon electrode P

Switch

Copper(II) sulphate solutions

Carbon

Cell 1

Cell 1


Larutan

kuprum(II) sulfat

Copper

Cell II

Cell II


V

Lead strip

Magnesium ribbon

M Electrolyte

Beaker

Ammeter

Porous pot

Zinc strip

Zinc sulphate aqueous 1M

Copper (II) sulfate aqueous 1M

Copper strip

A

Zinc

Copper

Copper(II) sulphate solution

V

Zinc

Copper

Copper(II) sulphate solution

V

1

05

2

3

Zinc and copper

Iron and copper

Magnesium and copper

Lead and copper

1

0

2

3

1

05

2

3

1

05

2

3

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module 14 electrolysis

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