science_final
kinetic molecular theory. This theory depict gas as composed of high-velocity particles that move in all directions.
Temperature and volume are quantities that can be used to describe a gas.
Temperature is the measure of the average kinetic energy of gas particles.
Volume is the amount of space occupied by these particles.
Another variable used to describe a gas is pressure.
Gas laws define the relationship between temperature, volume, pressure, and amount of gas at different conditions.
Boyle's Law In 1662, Anglo-Irish chemist Robert Boyle (1627- 1691) first observed the relationship between the pressure P and the volume V of a gas.
Charles's Law In 1787, French physicist Jacques Charles (1746-1823) observed the effect of temperature on the volume of a gas. He found out that gases expand by the same fractional amount when heated through the same temperature interval
absolute zero, or the lowest theoretically attainable temperature.
Gay-Loussac’s law in 1802, French chemist and physicist Joseph-Louis Gay-Lussac (1778-1850) established the relationship between the temperature and pressure of a gas.
Avogadro's law Ser of that at constant temperature and pressure, the volume of a gas is directly proportional to the number of moles of the gas.
This volume is known as the molar volume of a gas, which is equal to 22.4 L. The standard temperature and pressure is abbreviated to STP.
Ideal Gas Law Gases can be described in terms of the four variables ( p, T, V and n) combined into the single expression
where R is a proportionality constant known as the ideal gas constant. The equation is commonly written as
PV = nRT and represents the ideal gas law, which states that the volume of a gas varies directly with its quantity
An ideal gas satisfies all the assumptions of the kinetic molecular theory.
Carbohydrates are the most abundant class of organic compounds in organisms
The basic unit of carbohydrates are simple sugars, or monosaccharides.
When two simple sugars combine, the resulting carbohydrate is a disaccharide.
A long chain of repeating units of monosaccharides makes up a polysaccharide.
Monosaccharides are the simplest forms of sugar.
Those with an aldo group are called aldoses, while those with a keto group are ketoses.
Disaccharides are made up of two monosaccharide units joined by a glycosidic bond, a type of covalent bond.
hydrolysis, which breaks down a disaccharide into its monosaccharide units.
Polysaccharides are long chains of monosaccharide units. They are also referred to as polymers with high molecular masses.
Carbohydrates that contain an aldo group, which can be converted to a carboxylic acid group, are called reducing sugars
Under go Oxidation-reduction reaction
Starch can be detected using the iodine-potassium iodide reagent
Lipids are biomolecules that are either produced by the human body or obtained from diet.
Many lipids contain fatty acids, which consist of a long, hydrophobic (water-repelling), nonpolar ydrocarbon "tail" and a hydrophilic (water-loving), polar carboxylic acid functional group at the head."
Natural fatty acids may be saturated or unsaturated.
Saturated fatty acids have no carbon- abon double bonds.
unsaturated fatty acids contain one or more double bonds in the hydrocarbon
Trans-fatty acids, or trans fats, are formed through a process called hydrogenation
Cholesterol (C27H46O) is the most abundant steroid in animal tissues
Triacylglycerols, or triglycerides, are the most abundant class of lipids in plants and animals; they are stored forms of energy.
Esterification is the reaction between an alcohol and a carboxylic acid, which results in the formation of an ester and water.
usually of animal origin, are called fats; liquic triglycerides, usually of plant origin, are called oils.
Phospholipids are made up of glycerol, phosphate, a simple organic molecule, and two fatty acids.
Waxes are water-insoluble, low-melting solids that consist of a long-chain fatty acid and a long-chain monohydroxy alcohol
A chemical reaction is a process in which atoms of substances rearrange to form one or more new substances. It is accompanied by one or more observable changes in the reaction system as depicted in figure 16-1 on the next page.
Color change. Some reactions are accompanied by changes in the color of the substances. This is because the products of a reaction may have different physical properties, specifically color, compared to the original unreacted substances. For example, a once silvery metal can turn brownish orange, which is seen as rust.
Temperature change. A reaction system (or container) can become either hot or cold during a reaction. An increase in temperature means that the reaction releases heat, while a decrease in temperature signifies that the reaction absorbs heat.
Emission of light. A chemical reaction can produce light when it causes the potential energy of valence electrons to be released.
Evolution of gas. Gas is sometimes produced during a reaction, which can be observed as bubbles in the reaction mixture.
Precipitation. Some chemical reactions result in the formation of a solid insoluble substance called precipitate in a liquid medium.
Types of Reaction
· Combination a chemical reaction that involves two or more reactants (elements or compounds) that form a more complex substance is called combination or synthesis.
· Decomposition a reaction in which a compound is broken down into its component elements or into simplet compounds is called decomposition or analysis.
· Single Replacement a single replacement reaction, or substitution, is a type in which a more active free element, represented by X, replaces a less active element (B) in a compound. This type of reaction produces a new compound and an element.
· Double Replacement In a double replacement reaction (also known as double decomposition or metathesis), two compound exchange metallic (represented by A and b and nonmetallic (X and Y) ions to form two new compounds This is represented by the equation: dotom o tagla