Written By: Vishal Bhatt— Step 2 - Preparing Copper Sulphate Solution Fill copper sulphate powder to the brim of the prepared straw. The measuring cup can hold approximately 0.5

DIY AcidPreparation of acid through electrolysis of copper sulphate solution

Written By: Vishal Bhatt

DIY Acid Release: 2.3 [minor] 2019-08-11Guide ID: 569 -

This document was generated on 2019-10-06 03:50:04 AM (MST).

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INTRODUCTION

Acids are chemical substances which have a pH below 7, can corrode metals and can turn a bluelitmus paper into red colour. In this guide, we are going to prepare acid by the electrolysis of coppersulphate solution.

TOOLS:Scissors (1)Plastic Bottle (1)DIY Battery Holder (1)Ruler (1)Insulation Tape (1)

PARTS:Water (1)

30 mlpH Paper Strip (2)Copper Sulphate Powder (1)

0.5 gFat Straw (1)

10 cmGraphite Rod or Pencil lead (2)Copper Strip (1)

2 cm x 5 cmFilter Paper (1)Transparent Plastic Container (1)

Urine Sample30 ml



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— Precautions

Handle acid carefully once it is prepared.

Do not ingest any materials.

Scissors have sharp edges. Handle with care.

— Prerequisite Guide - DIY Battery Holder

The DIY Battery Holder is designed to provide 3V, using two AA batteries along with foam,aluminium tape, connecting wire and a cardboard base. For more details on making a DIY BatteryHolder, please go to DIY Battery Holder.

— Step 1 - Making a Measuring Cup

Take a fat straw and measure 7 mm, using a ruler, from one of its ends. Mark a line at 7 mm onthe straw.

Using scissors, cut the straw at the marked line.

Seal one end of the cut straw piece with an insulation tape. Now, the straw measuring cup is ready.



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https://www.tactivity.in/Guide/DIY+Battery+Holder/637

— Step 2 - Preparing Copper Sulphate Solution

Fill copper sulphate powder to the brim of the prepared straw.

The measuring cup can hold approximately 0.5 g of copper sulphate powder.

Take 30 ml of water in a transparent plastic container. Pour the contents (copper sulphate) of themeasuring cup into it.

Stir till the copper sulphate powser dissolves completely in water.

The copper sulphate solution inside the transparent plastic container will be our electrolyte.

— Step 3 - Initial pH Test for Copper Sulphate Solution

Dip a pH paper strip into the copper sulphate solution.

pH paper is used to find the nature (acidic/basic/neutral) and strength of the copper sulphatesolution.

Compare the pH paper strip with the pH scale.



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— Step 4 - Preparing the Copper Electrode

Take a copper strip and fold it at 5 mm, from one of its ends.

At the centre of the folding, cut a small triangle with the help of scissors.

When you open the copper strip folding, you will see a diamond shaped hole in it.

Insert one end of a connecting wire (with the insulation removed), in the diamond shaped hole andattach it to the copper strip.



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— Step 5 - Preparing the Battery Setup

Connect the pencil leads, using a connecting wire, to the positive terminal of the battery.

Positive terminal of the battery is identified by a bump, whereas negative terminal is identified bythe absence of it.

Pencil leads connected to the positive terminal of the battery will be our anode (positive electrode).

Connect the negative lead (shorter leg) of the LED to the negative terminal of the battery. Connectthe positive lead (longer leg) of the LED to the copper strip.

The copper strip connected to the negative terminal of the battery, via the LED, will be our cathode(negative electrode).

Here, an LED is used to indicate the continuous flow of current.

The connected setup of the battery with the electrodes and an electrolyte is as shown, in the nextsection.



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— Step 6 - Set Up for Electrolysis

Insert both the electrodes into the electrolyte.

Observe the bubbles on the pencil leads (anode).

Bubbles are formed due to the evolution of oxygen gas.

Observe the colour of copper strip (cathode).

Colour change is due to the deposition of copper.

— Step 7 - Complete Electrolysis

After about two hours, the colour ofthe solution will turn light blue.

Majority of the copper sulphatesolution would have turned intosulphuric acid.

The resultant acid and its strengthwill be determined using a pH paperstrip.



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— Step 8 - Filtration Setup

Take a waste plastic bottle and cut it, at about 1/3rd the distance from the cap, such that you get a"funnel" (top part of the bottle) and a "beaker" (bottom part of the bottle).

Take a filter paper and fold it into a cone, as shown.

Insert the filter paper into the funnel (top cut part of the bottle) and place the funnel inside thebeaker.

Filter the solution, from the plastic container using this filtration setup.



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— Step 9 - pH Test for Acid (Sulphuric Acid)

Dip a pH paper strip into the filtered solution.

Compare the pH paper strip with the pH scale.

— Troubleshooting

The desired result may not be obtained due to the following reasons -

Incorrect measurement of copper sulphate.

Incorrect connections of the cathode (copper) and anode (pencil leads) to the battery setup.

Using contaminated containers.

Disconnecting the connection before the copper gets deposited.



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— Suggested Variations

Vary the amount of electrolyte (copper sulphate) used; observe and record the changes.

Change both the electrodes to pencil leads; observe and record the changes.

To learn more about the variations of DIY Acid, please go to DIY Acid (Variations)



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Documents

Written By: Vishal Bhatt— Step 2 - Preparing Copper Sulphate Solution Fill copper sulphate powder to the brim of the prepared straw. The measuring cup can hold approximately 0.5