How to Write a Summary of an Article? Whitty, Science 10 Fiona Adams, November 1st, Introduction Chemical reactions are a part of our daily lives, from rusting metal to making bread to leaves changing colour in the fall.
For the previous version, see this page. Chemical reactions happen absolutely everywhere. While we sometimes associate chemical reactions with the sterile environment of the test tube and the laboratory - nothing could be further from the truth. In fact, the colossal number of transformations make for a dizzying, almost incomprehensible array of new substances and energy changes that take place in our world every second of every day.
Whether it be a fire raging across a forest Figure 1the slow process of iron rusting in the presence of oxygen and water over a period of years, or the delicate way in which fruit ripens on a tree, the process of converting one set of chemical substances the reactants to another set of substances the products is one known as a chemical reaction.
A controlled fire in Alberta, Canada, set to create a barrier for future wildfires. Processes like fermentation, in which sugars are chemically converted into alcoholhave been known for centuries; however, the chemical basis of the reaction was not understood.
What were these transformations and how were they controlled?
These questions could only be answered when the transition from alchemy to chemistry as a quantitative and experimental science took place. Simple stones, such as those that contained sulfur, seemed to magically burn; and otherwise unimpressive minerals were transformed, like the ore cinnabar becoming an enchanting silvery liquid metal mercury when heated.
Aristotle believed that everything in the world was composed of four fundamental substances - air, earth, fire, and water. As such, they proposed, and spent generations trying to prove, that less expensive metals like copper and mercury could be turned into gold.
Despite their misguided approach, many early alchemists performed foundational chemical experiments - transforming one substance into another, and so it is difficult to point to a specific date or event as the birth of the idea of an ordered, quantifiable chemical reaction. However, there are some important moments in history that have helped to make sense of it.
Law of Mass Conservation Antoine Lavoisier was a French nobleman in the s who began to experiment with different chemical reactions.
In doing so, Lavoisier championed the idea of conservation of mass during transformations Figure 3. In other words, unlike the alchemists before him who thought that they were creating matter out of nothing, Lavoisier proposed that substances are neither created nor destroyed, but rather change form during reactions.
Lavoisier's Law of Mass Conservation, which states that substances are neither created nor destroyed, but rather change form during reactions.
In this example, the reactants zinc and two hydrogen chloride molecules convert into different products zinc chloride and dihydrogenbut no mass is lost or created. Proust performed dozens of chemical reactionsstarting with different amounts of various materials.
Over time he observed that no matter how he started a certain chemical reactionthe ratio in which the reactants were consumed was always constant.
For example, he worked extensively with copper carbonate and no matter how he changed the ratio of starting reactants, the copper, carbon, and oxygen all reacted together in a constant ratio Proust, As a result, in the last few years of the 18th century, Proust formulated the law of constant composition also referred to as the law of definite proportions, Figure 4.
He realized that any given chemical substance that we now define as a compound always consisted of the same ratio by mass of its elemental parts regardless of the method of preparation. This was a huge step forward in modern chemistry since it had been previously believed that the substances formed during chemical reactions were random and disordered.Essay On The Chemical Reations And The Ph Scale pH pH means Power of Hydrogen or Potential of HydrogenpH is a scale of acidity from 0 to It tells how acidic or alkaline a substance is.
More acidic solutions have lower benjaminpohle.com alkaline solutions have higher benjaminpohle.comnces which are not acidic or alkaline i.e neutral usually have a pH of around 7. Traditionally, an acid (from the Latin acidus or acere meaning sour) was any chemical compound that, when dissolv Bases are the chemical opposite of acids.
i.e. a pH less than Correspondingly, a base was any compound that, when dissolved in water, gives a solution with a hydrogen ion activity Acid vs Base. Anonymous comments (5). List the different types of chemical reactions and give a brief description.
Synthesis, decomposition, single displacement, and double displacement. A synthesis reaction occurs when two elements or compounds combine to form a more complex molecule.
Chemical equations represent what occurs in a chemical reaction.
For example, the equation HCl (aq) LPCK (Jeschofnig, Peter., Ph.D., "Physical and Chemical Properties." General College Chemistry. Englewood, CO: Hands on Lab Inc., 0. Print.) First, I followed all safety measures as outlined therein. Essay on Chemical.
This tutorial introduces basics of acids and bases. Other sections include matter, elements, the periodic table, and biochemistry. Scientists use something called the pH scale to measure how acidic or basic a liquid is.
NEXT PAGE ON CHEMICAL REACTIONS ACIDS AND BASES QUIZ RETURN TO TOP OF PAGE Or search the sites. Acids and bases play a central role in chemistry because, with the exception of redox reactions, every chemical reaction can be classified an as acid-base reaction/5(5).