Chemistry
Chemistry projects for class 11 and 12: 33 ideas.
Each project below opens to its own page with what it shows, the science behind it, the materials, safety, step-by-step instructions, what you should see and viva questions. Many can be made from things at home; where a kit helps, the page links one.
Other subjects for class 11 and 12: Physics, Biology, Maths, Earth and space, Electronics and robotics, Environment, Computing and coding.
Electrolysis of water
An electric current splits water into hydrogen at the negative electrode and oxygen at the positive one. About twice as much hydrogen as oxygen collects, which matches the formula H₂O.
Vitamin C in fruit juices
Vitamin C reacts with iodine. When iodine solution is added drop by drop to a juice containing starch, the blue-black colour appears only after all the vitamin C is used up, so more drops mean more vitamin C.
Foaming capacity of soaps
Soaps differ in how much lather they make. In hard water, calcium and magnesium salts react with soap to form scum, so less foam forms.
Temperature and the rate of a reaction
An effervescent tablet dissolves faster in warm water, because the particles move faster and collide more often and with more energy. Crushing the tablet speeds it up too, by giving it more surface area.
Oxalate in guava as it ripens
Guava contains oxalate ions. Titrating extracts of raw, half-ripe and ripe guava with potassium permanganate shows how the amount of oxalate changes as the fruit ripens.
Simple food adulteration tests
Some adulterants show up with simple tests: starch in milk, paneer or khoa turns blue-black with iodine, and sawdust or brick powder in spices floats or settles when the powder is sprinkled on water.
Comparing water hardness of local samples by soap drop count
Hard water contains dissolved calcium and magnesium salts that react with soap to form scum before any lather can form. Counting the drops of a standard soap solution needed to get a lasting lather ranks tap, borewell, RO, rain and bottled water from softest to hardest.
Does boiling soften water? Temporary against permanent hardness
Temporary hardness, caused by calcium and magnesium bicarbonates, is removed by boiling, which deposits them as carbonate scale. Permanent hardness from sulphates and chlorides is not. Testing a sample before and after boiling, and after adding washing soda, shows which kind of hardness it has.
Rate of reaction and concentration: vinegar strength by mass loss
When baking soda reacts with vinegar, the carbon dioxide escapes and the flask gets lighter. Following the mass on a balance every 30 seconds gives a rate curve, and repeating with diluted vinegar shows that the rate falls as the acid concentration falls, while the total gas depends only on how much acid was present.
Electroplating a steel key with copper from copper sulphate
Passing a small current through copper sulphate solution deposits a layer of copper on the object connected to the negative terminal, while the copper anode slowly dissolves to replace the copper ions. A clean steel key or coin comes out with a bright copper coating.
Mass of copper deposited against time: testing Faraday’s law
The mass of copper deposited in electrolysis is proportional to the charge passed, that is current multiplied by time. Weighing the cathode after fixed intervals at a steady current gives a straight line, and the slope lets you estimate Faraday’s constant from school equipment.
Soap against detergent: lather height in hard and soft water
Soap forms insoluble scum with the calcium and magnesium in hard water and lathers poorly, while a synthetic detergent forms soluble calcium salts and lathers almost as well in hard water as in soft. Measuring foam height for both cleaners in water of increasing hardness makes the difference visible and numerical.
pH of tea and coffee against brewing time and added milk
Tea and coffee are mildly acidic, and the acidity depends on how long they brew and whether milk is added. Measuring pH with indicator paper for black tea, green tea and coffee brewed for different times shows how extraction of acids changes with time and how milk partly neutralises them.
Corrosion rate of iron nails against salt concentration
Rusting is an electrochemical process that speeds up when the water conducts better. Nails kept in water with 0, 1, 3.5 and 10 percent salt for two weeks, then cleaned and weighed, show that salt accelerates corrosion, which is why vehicles and ships near the sea rust faster, and also that very strong brine slows it again.
Sacrificial protection: zinc-wrapped against copper-wrapped nails
An iron nail wrapped with zinc stays bright in salt water because the more reactive zinc corrodes instead, while a nail wrapped with copper rusts faster than a bare nail because copper makes the iron the more reactive partner. This is the chemistry of galvanised sheets and the zinc blocks bolted to ship hulls.
Comparing vinegar brands by drop titration with washing soda
The acetic acid content of vinegar can be compared by titrating a measured volume with a standard washing soda solution until an indicator changes colour. Running three brands and a home-made dilution ranks them by strength and, with a simple calculation, gives an approximate percentage of acid to compare with the label.
Which antacid neutralises the most acid? A vinegar drop count
Antacids are bases or salts of weak acids that react with acid and neutralise it. Counting how many drops of vinegar one tablet can neutralise lets you compare brands fairly, per tablet and per gram.
How much calcium carbonate is in an eggshell? Mass loss in vinegar
Eggshell is mostly calcium carbonate. When it reacts with vinegar it gives off carbon dioxide, so the loss in mass of the flask tells you how much calcium carbonate was present.
Hot or cold? Temperature change when different solids dissolve
Dissolving some solids makes the water colder (endothermic) and dissolving others makes it warmer (exothermic). The reason is the balance between the energy needed to break the solid apart and the energy released as water surrounds the particles.
Iron nail in copper sulphate: weighing the copper that appears
A more reactive metal pushes a less reactive metal out of its salt solution. Iron displaces copper from copper sulphate, and the mass of copper formed can be compared with the mass of iron used.
Cooling curve of candle wax: where the temperature stops falling
When liquid wax freezes it gives out latent heat, so the temperature stays nearly steady while it solidifies. The flat part of the cooling curve marks the freezing point.
Does salt raise the boiling point of water? A measured test
A dissolved solid raises the boiling point of water, and the rise grows with the amount of solute. This is called boiling point elevation and is a colligative property.
Phitkari loses nearly half its mass: water of crystallisation
Crystals of potash alum contain water locked in their structure. On heating the water is driven off as steam and the crystal puffs up into a white powder that weighs much less than before.
Solubility curves: alum rises steeply with heat, salt hardly moves
Solubility is the mass of solute that dissolves in a fixed amount of water at a given temperature. A plotted curve shows that for alum it rises sharply with temperature, and for common salt it hardly changes.
Charles’s law with a sealed syringe in cold and hot water baths
A fixed amount of gas at constant pressure expands steadily as its temperature rises. A graph of volume against temperature is a straight line that points to about minus 273 degrees C.
Vitamin C clock: a colourless mix that turns blue on time
In a clock reaction nothing seems to happen for a measured time and then the colour changes suddenly. The delay depends on how much vitamin C is present, so the time can be used to measure concentration.
Catalyst race: which kitchen catalyst breaks down hydrogen peroxide fastest?
Catalysts speed up a reaction without being used up. Yeast and raw potato contain catalase, an enzyme that breaks hydrogen peroxide into water and oxygen, and the volume of oxygen collected measures how fast it works.
Daniell cell with a paper salt bridge: measuring 1 volt from two metals
A chemical cell turns the energy of a redox reaction into electricity. Zinc and copper in their salt solutions, joined by a salt bridge, give a voltage of about 1 volt that falls as the reaction proceeds.
Dyeing cotton with turmeric and onion skin: does a mordant help?
Many natural dyes wash out of cotton unless a mordant is used. A mordant such as alum forms a link between the dye and the fibre, making the colour stronger and more lasting.
Spinach leaf pigments separated by paper chromatography with Rf values
A green leaf contains several pigments. Paper chromatography separates them because they travel up the paper at different speeds, and the ratio of distances, the Rf value, identifies each one.
Hot ice: making sodium acetate that freezes warm from baking soda
A supersaturated solution holds more solute than it normally should. Touching it with one seed crystal sets off fast crystallisation that gives out heat, so the liquid turns into a warm solid.
Alum against moringa seed powder: which clears muddy water faster?
Coagulants make tiny suspended particles clump together and sink. Comparing alum (phitkari) with crushed moringa seed shows two ways to clear turbid water before filtering.
Vitamin C in raw and boiled vegetables with iodine and starch
Vitamin C is destroyed by heat and dissolves in cooking water. A starch and iodine indicator that loses its blue colour when vitamin C is present lets you compare how much each sample contains.