Chemistry Revision: Chemical Reactions

A chemical reaction is a process where one or more substances, called reactants, are transformed into one or more different substances, called products.

A balanced chemical equation is one where the number of atoms of each element on the reactant side is equal to the number of atoms of that element on the product side.

An unbalanced chemical equation is one where the number of atoms of each element on the reactant side is not equal to the number of atoms of that element on the product side.

<p>The law of conservation of mass states that in a closed system, the total mass of the reactants before a chemical reaction must equal the total mass of the products after the reaction.</p> Signup and view all the answers

<p>Chemical equations are balanced to obey the law of conservation of mass, ensuring that the number of atoms of each element remains the same on both sides of the equation.</p> Signup and view all the answers

<p>A combination or synthesis reaction is a type of chemical reaction where two or more reactants combine to form a single product.</p> Signup and view all the answers

<p>A decomposition or breakdown reaction is a type of chemical reaction where a single reactant breaks down into two or more products.</p> Signup and view all the answers

<p>An exothermic reaction is a chemical reaction that releases heat energy into the surroundings.</p> Signup and view all the answers

<p>A displacement or single displacement reaction is a type of chemical reaction where a more reactive element displaces a less reactive element from its compound.</p> Signup and view all the answers

<p>A double displacement reaction is a type of chemical reaction where two reactants exchange ions to form two new products.</p> Signup and view all the answers

<p>Oxidation refers to the loss of electrons, gain of oxygen, or loss of hydrogen by a substance.</p> Signup and view all the answers

<p>A redox reaction is a chemical reaction involving both oxidation and reduction.</p> Signup and view all the answers

<p>Corrosion is the gradual degradation of a material due to chemical or electrochemical reactions with its environment.</p> Signup and view all the answers

<p>Rancidity is the spoilage of fats and oils, usually caused by oxidation, resulting in unpleasant taste, odor, and appearance.</p> Signup and view all the answers

<p>Neutralization is a chemical reaction between an acid and a base, resulting in the formation of salt and water.</p> Signup and view all the answers

<p>A precipitate is a solid that forms from a solution during a chemical reaction.</p> Signup and view all the answers

<p>Roasting is a process where a sulfide ore is heated in the presence of air to convert it into its oxide form.</p> Signup and view all the answers

<p>An amalgam is an alloy of mercury with another metal.</p> Signup and view all the answers

<p>Metallurgy is the science and technology of extracting metals from their ores and refining them into useful forms.</p> Signup and view all the answers

<p>Amphoteric oxides are oxides that can act as both acids and bases.</p> Signup and view all the answers

<p>A chemical bond is a force of attraction that holds atoms together in a molecule or compound.</p> Signup and view all the answers

<p>An ionic bond is formed by the transfer of electrons between a metal and a non-metal.</p> Signup and view all the answers

<p>A covalent bond is formed by the sharing of electrons between two nonmetal atoms.</p> Signup and view all the answers

<p>Sodium metal is highly reactive and reacts readily with oxygen and water in the air, causing a fire. To prevent this, it is stored in kerosene.</p> Signup and view all the answers

<p>Isomers are molecules that share the same molecular formula (same types and numbers of atoms) but have different arrangements of those atoms.</p> Signup and view all the answers

<p>Halogenation is a chemical reaction where a halogen atom (like chlorine, bromine, or iodine) is added to a molecule.</p> Signup and view all the answers

<p>Saponification is the process of making soap by reacting a fat or oil with a strong alkali, such as sodium hydroxide.</p> Signup and view all the answers

<p>A detergent is a surfactant that helps remove dirt and grime from surfaces.</p> Signup and view all the answers

<p>Fossil fuels are naturally occurring fuels formed over millions of years from the decomposed remains of ancient organisms.</p> Signup and view all the answers

<p>A hydrocarbon is a compound composed only of carbon and hydrogen atoms.</p> Signup and view all the answers

<p>A functional group is a specific group of atoms within a molecule that is responsible for the characteristic chemical properties of that molecule.</p> Signup and view all the answers

<p>A homologous series is a group of organic compounds with the same general formula, similar chemical properties, and a gradual change in physical properties.</p> Signup and view all the answers

<p>The vital force theory suggested that organic compounds could only be produced by living organisms due to a mysterious &quot;vital force&quot; that was absent in nonliving matter.</p> Signup and view all the answers

<p>Water conservation or rainwater harvesting refers to the methods and techniques used to collect, store, and manage rainwater, reducing dependence on conventional sources and improving water security.</p> Signup and view all the answers

<p>Mendeleev's periodic table arranged elements in order of increasing atomic mass while the modern periodic table arranges them in order of increasing atomic numbers.</p> Signup and view all the answers

<p>The atomic number of an element represents the number of protons in its nucleus, it is a fundamental property of an element.</p> Signup and view all the answers

<p>RRR refers to the practice of &quot;Reduce, Reuse, and Recycle&quot;, which is an effective strategy for managing resources and minimizing waste.</p> Signup and view all the answers

<p>Environmental management is the systematic process of planning, implementing, and monitoring activities to achieve environmental goals.</p> Signup and view all the answers

<p>The modern periodic law states that the properties of elements are a periodic function of their atomic numbers.</p> Signup and view all the answers

<p>Non-conventional energy sources are renewable and sustainable energy sources that are different from the traditional fossil fuel sources and can be used for power generation.</p> Signup and view all the answers

<p>Solar energy is a versatile energy source used for generating electricity, heating water, cooking food, and powering homes and businesses.</p> Signup and view all the answers

<p>Biogas is a combustible gas generated from the breakdown of organic matter, such as plant or animal waste, in an oxygen-free environment.</p> Signup and view all the answers

<p>Soap is made from fats or oils, while detergents are synthetically produced. Soap doesn't work well in hard water, but detergents work in both hard and soft water.</p> Signup and view all the answers

<p>A catalyst is a substance that speeds up a chemical reaction without being consumed in the reaction.</p> Signup and view all the answers

<p>Deforestation has drastic effects on wildlife, including habitat loss, fragmentation, and disruption of food chains.</p> Signup and view all the answers

<p>Deforestation contributes to climate change, soil erosion, and loss of biodiversity by degrading habitats, reducing carbon sinks, and disrupting natural ecosystems.</p> Signup and view all the answers

<p>A functional group is a specific group of atoms within a molecule that gives it its characteristic chemical properties.</p> Signup and view all the answers

<p>Carbon atoms can form long chains, rings, and branched structures, and they can also bond with other elements like hydrogen, oxygen, nitrogen, and halogens.</p> Signup and view all the answers

<p>Copper is a good conductor of heat and is corrosion-resistant, making it an ideal material for hot water tanks.</p> Signup and view all the answers