Chemical Reactions Examples

What is a Chemical Reaction?  

A chemical reaction is a process that involves the transformation of one or more substances into new substances with different physical and chemical properties.

In other words, it is a process where reactants are transformed into products through the rearrangement of atoms. During a chemical reaction, the bonds between atoms are broken, and new bonds are formed, forming different substances.

  
Chemical reactions can occur in various settings and can be triggered by multiple factors, including heat, light, pressure, and catalysts. Some chemical reactions are reversible, meaning the products can be converted back into the original reactants under the right conditions.

Chemical reactions can also produce energy, as the bonds in the starting molecules are broken, and new bonds are formed. In some responses, like combustion, energy is released as a by-product. In other reactions, like photosynthesis, energy is absorbed.  

Different Types of Chemical Reactions  

There are several diverse types of chemical reactions, each with distinct characteristics. Some of the most common types of chemical reactions include:  

• Combination reaction: A combination reaction is when two or more substances combine to form a single, more complex product.   
• Decomposition reaction: A decomposition reaction is the opposite of a combination reaction.   
• Single replacement reaction: In a single replacement reaction, one element replaces another element in a compound.   
• Double replacement reaction: A double replacement reaction occurs when two compounds produce two new compounds.   
• Acid-base neutralization reaction: An acid-base neutralization reaction occurs when an acid reacts with a base to form a salt and water.   
• Redox reaction: A redox reaction is a type of reaction that involves the transfer of electrons between reactants. In these reactions, one reactant is oxidized (loses electrons) while the other is reduced (gains electrons).   

Chemical Reaction - Examples  

Chemical reactions are common occurrences in everyday life. Here are some natural examples of chemical reactions:  

• Combustion of wood: When wood burns, it undergoes a chemical reaction with oxygen in the air, producing carbon dioxide, water vapor, and heat.  
• Respiration: When humans and animals breathe, they take in oxygen and exhale carbon dioxide. This is a chemical reaction in which oxygen is used to break down glucose and produce energy.  
• Rusting of iron: When iron is exposed to oxygen and water, it undergoes a chemical reaction called oxidation, forming rust.  
• Photosynthesis: In plants, sunlight converts carbon dioxide and water into glucose and oxygen through a complex series of chemical reactions.  
• Digestion: When food is consumed, it undergoes a series of chemical reactions in the digestive system that break it down into nutrients the body can use.  
• Fermentation: In producing beer, wine, and bread, yeast or bacteria convert sugar into alcohol or carbon dioxide through a chemical reaction.  
• Decay: When organic matter such as leaves, food, or animals decompose, they undergo a chemical reaction that releases gases and nutrients back into the environment.  
• Weathering: Rocks and minerals can undergo chemical reactions with water, air, and other environmental substances, causing them to break down or change composition over time.  

Chemical reactions are essential to many processes in the natural world, including the growth and reproduction of living organisms, the formation and decomposition of minerals, and the production of energy. They are also used in various human activities, such as the production of food, fuels, medicines, and industrial materials.  

Example of Incomplete Dominance

Austrian monk Gregor Johan Mendel uncovered important insights concerning heredity. Mendel was the first to foresee the features handed down from parents to children.

He is referred to as "The Father of Genetics" since he uncovered the fundamentals of the field. Mendel experimented with garden pea hybrids between 1856 and 1863. (Pisum sativum). He decided on a few distinctive qualities of the peas throughout that time.  

Mendel's Law of Inheritance

Mendel's inheritance laws describe how traits are passed down from parents to offspring. These laws were discovered by Gregor Mendel, an Austrian monk, and botanist, in the mid-19th century. Mendel's experiments involved breeding pea plants and carefully tracking the inheritance of specific traits over multiple generations.  

• The Law of Segregation states that when gametes develop, alleles segregate, and each gamete bears a single copy of each gene.  
• The rule of independently varying: Alleles for one gene segregate independently of alleles for other genes.  
• The Law of Dominance states that an organism with two possible gene variants will express the dominant form.  

Mendel's laws provide the foundation for our understanding of genetics and heredity. They help explain why offspring inherit specific traits from their parents and how new variations of characteristics arise over time through genetic mutations and recombination.  

Incomplete Dominance  

When an organism's phenotype reflects a mixing of both alleles, this phenomenon is known as incomplete dominance. It occurs when a dominant allele or gene form does not entirely conceal or disguise the effects of a recessive allele.

Snapdragon is a prime example of imperfect dominance (Antirrhinum majus). Pink flowers result from a cross between a homozygous parent with white flowers and a homozygous parent with red blooms.  

Examples:   

Wavy hair is an example of incomplete dominance in humans. The two alleles for curly or straight hair are present. If a person has homozygosity for both alleles, their hair will be straight or curly. However, suppose a person inherits one gene for curly hair and one allele for straight hair.

In that case, they will have wavy hair if heterozygous for hair texture because the two alleles interact to produce a distinct phenotype, indicative of incomplete dominance.  

Co-Dominance  

Co-dominance is an inheritance pattern where both alleles (versions of a gene) in a heterozygous individual (an individual with two different alleles for a particular gene) are expressed equally in the phenotype. In other words, neither allele is dominant nor recessive, and both contribute to the individual's physical appearance.  

Co-dominance differs from incomplete dominance, where the heterozygous phenotype is a blend of the two alleles, such as in the case of pink flowers resulting from the combination of red and white flower alleles.  

Examples:  

In humans, the ABO blood group system is controlled by three alleles: A, B, and O. Alleles A and B are co-dominant, meaning that if an individual inherits one A allele and one B allele, they will express both A and B antigens on their red blood cells, resulting in AB blood type.  

Another example of co-dominance can be seen in the case of roan cattle, which have a coat color that is a mixture of red and white hairs. This is because the alleles for red and white coats are both co-dominant, resulting in a blended appearance.