Where you see manufactured substances in industry in everyday life

The manufactured substances in industry chapter can feel like a list of factory processes with little to do with your life. In fact you are surrounded by its products: the cutlery you eat with, the fertiliser that grew your rice, the glass in your window and the concrete under your feet. This article walks through those everyday materials and links them back to the chemistry SPM asks you to explain.

Alloys: metals made better

Pure metals are often too soft or corrode too easily to be useful, so we mix them into alloys. Stainless steel, iron with chromium and nickel, resists rust, which is why it makes cutlery, sinks and kitchen tools. Brass (copper and zinc) is hard-wearing and attractive, used in taps and instruments; bronze (copper and tin) makes medals and statues; duralumin (aluminium with copper and magnesium) is light yet strong for aircraft. Malaysia has its own proud example: pewter, a tin-based alloy, is crafted here into tankards and ornaments.

The SPM explanation matters. In a pure metal the atoms are the same size and arranged in orderly layers that slide over one another, so the metal is soft. Adding atoms of a different size disrupts the orderly arrangement, so the layers can no longer slide easily, the alloy is harder and stronger. Alloying can also improve resistance to corrosion and appearance.

Sulfuric acid: the chemical you never see but always use

Sulfuric acid, H₂SO₄, is one of the most produced chemicals in the world. It is inside car batteries, and it is used to make detergents, paints, fertilisers and fibres. It is manufactured by the Contact process, which SPM expects you to know in outline: sulfur is burned to sulfur dioxide, which is then oxidised to sulfur trioxide over a vanadium(V) oxide catalyst at about 450 °C:

2SO₂ + O₂ ⇌ 2SO₃

The sulfur trioxide is dissolved in concentrated sulfuric acid to form oleum, which is then diluted with water to give more acid. Follow the full sequence in the Contact process page.

Ammonia and fertilisers: feeding the crops

The nitrogen that lets plants grow reaches the soil through ammonia and its salts. Ammonia is made by the Haber process, combining nitrogen from the air with hydrogen over an iron catalyst at high temperature and pressure:

N₂ + 3H₂ ⇌ 2NH₃

Ammonia is then turned into fertiliser salts such as ammonium nitrate, ammonium sulfate and urea, which supply nitrogen for leaf growth. When you eat rice or vegetables grown on a Malaysian farm, the Haber process helped grow them. Ammonia solution also appears in household cleaners.

Glass and ceramics: windows, mugs and cookware

Ordinary windows and bottles are soda-lime glass, made by melting sand (silicon dioxide) with sodium carbonate and limestone. Heat-resistant cookware uses borosilicate glass, which expands very little on heating so it does not crack, the reason a laboratory beaker or a glass casserole survives sudden temperature changes. Ceramics are made from clay hardened by firing: floor tiles, mugs, bricks, electrical insulators and the white part of a spark plug are all ceramics, valued for being hard, heat-resistant and chemically inert.

Composite materials: the best of two worlds

A composite material combines two materials so the mixture beats either one alone. Reinforced concrete, concrete poured around steel bars, has the compressive strength of concrete and the tensile strength of steel, which is why it holds up bridges and high-rise buildings. Fibreglass, glass fibres set in plastic, is light, strong and waterproof, so it forms boat hulls, helmets and car bodies. Photochromic glass, used in sunglasses that darken in bright light, is another composite you may wear.

Why the conditions are a compromise

Both named processes hide a lesson SPM likes to test: the chosen temperature and pressure are a compromise, not the value that gives the most product. In the Contact and Haber processes the forward reaction is exothermic, so a low temperature would favour more product at equilibrium, but a low temperature also makes the reaction too slow to be useful. Industry therefore settles on a moderate temperature that gives a reasonable yield at a workable rate. High pressure favours the side with fewer gas molecules in the Haber process, but very high pressure is expensive and dangerous, so a moderate pressure is used instead. Being able to explain these trade-offs, rather than just quoting the numbers, is what separates a full-mark answer from a half one.

Making the chapter stick

The trick with this chapter is to attach each process to a real object. Hold a stainless-steel spoon and recall why alloying hardens it; look at a bag of fertiliser and recall the Haber process; tap a concrete pillar and recall what makes a composite strong. Learn the two named processes, Contact and Haber, with their catalysts and equations, because they are examined most often.

If the industrial processes and their conditions keep slipping, a short online one-to-one lesson can help you build a single clear summary of each, with the equations and everyday uses side by side. Our teachers teach in English from RM50 an hour, and you can start with a paid one-hour trial to see how it works.