Home / Free Subjects / chemistry

Brass is an alloy primarily composed of copper and zinc. Bronze is an alloy of copper and tin. Steel is an alloy of iron and carbon

The atomic number (Z) equals the number of protons and, in a neutral atom, the number of electrons. The mass number (A) is the sum of protons and neutrons. For this element, protons = 17, electrons = 17. $Neutrons = Mass Number - Atomic Number = 35 - 17 = 18$

Hard water contains dissolved calcium and magnesium salts. These ions react with soap to form an insoluble precipitate called scum, which prevents the soap from lathering and can stain clothes and fixtures. This leads to a waste of soap.

Alkenes undergo an addition reaction with bromine water. The reddish-brown color of the bromine water is decolorized as the bromine atoms add across the double bond. This serves as a chemical test to distinguish between saturated alkanes and unsaturated alkenes.

In the electrolytic purification of copper, an impure copper block is used as the anode, and a thin strip of pure copper serves as the cathode. When electricity is passed through the copper(II) tetraoxosulphate(VI) electrolyte, copper ions from the anode dissolve and are deposited as pure copper on the cathode

The production of local gin (a form of ethanol) from palm wine involves a two-step process: first, fermentation where microorganisms convert sugars into ethanol and carbon dioxide, and second, distillation to concentrate the ethanol and separate it from other components of the mixture

The compound $HOOC-COOH$ has two carbon atoms and two carboxyl functional groups. The IUPAC naming for dicarboxylic acids is based on the parent alkane name with the suffix "-dioic acid." For a two-carbon chain, the parent alkane is ethane, so the name is ethanedioic acid, commonly known as oxalic acid

Carbohydrates are classified into monosaccharides, disaccharides, and polysaccharides. Glucose is a simple sugar, a monosaccharide, which is the basic unit of more complex carbohydrates like starch and cellulose

This reaction is a classic example of a reversible reaction, where dinitrogen tetroxide ($N_2O_4$ ) can be converted into nitrogen dioxide ($NO_2$ ), and the nitrogen dioxide can also be converted back into dinitrogen tetroxide. The double arrow ($\rightleftharpoons$ ) indicates that the reaction proceeds in both the forward and reverse directions

The Haber process is the industrial method for synthesizing ammonia from nitrogen and hydrogen gases. It involves reacting nitrogen from the air with hydrogen, which is typically obtained from natural gas or petroleum, under high temperature and pressure in the presence of an iron catalyst.

Increasing the temperature increases the kinetic energy of the reactant molecules. This leads to more frequent and energetic collisions, and a greater proportion of molecules possessing the necessary activation energy, thus increasing the reaction rate

A supersaturated solution contains more dissolved solute than a saturated solution at that temperature. It is a metastable state, and the excess solute will often crystallize out if disturbed

Oil spillage is a significant source of soil pollution, particularly in the Niger Delta region of Nigeria. Crude oil contains many non-biodegradable components that persist in the soil, making it unsuitable for agriculture and disrupting ecosystems

Saponification is the hydrolysis of an ester (like fats and oils) using a strong alkali (like sodium hydroxide) to produce soap (a metallic salt of a fatty acid) and glycerol

Carbon(II) oxide (carbon monoxide, CO) is a colorless, odorless, and highly toxic gas produced by the incomplete combustion of carbon-containing fuels. It binds strongly to the hemoglobin in blood, preventing it from carrying oxygen, which can lead to asphyxiation

The Solvay process, also known as the ammonia-soda process, uses sodium chloride (brine) and limestone ($CaCO_3$ ) as its main raw materials to produce sodium carbonate

Brownian movement is the random, erratic motion of microscopic particles suspended in a fluid (liquid or gas) or the air, resulting from their collision with the fast-moving atoms or molecules in the fluid.

Boyle's law states that for a fixed mass of gas at constant temperature, the pressure is inversely proportional to the volume $(P \propto \frac{1}{V})$ . Therefore, if the pressure is tripled, the volume will decrease to one-third of its original value.

Air is a mixture because its components, like nitrogen, oxygen, and argon, are not chemically bonded to each other. They can be separated physically, for example, by fractional distillation of liquid air

True solutions have very small solute particles (less than 1 nm) that cannot be seen with a microscope. Colloids have larger particles (1-1000 nm) that are uniformly dispersed and do not settle out. Suspensions have the largest particles (greater than 1000 nm) that will settle over time