#4th grading

Molarity

Molarity is defined to be the number of moles of a solute divided by the liters of a solution. It has a unit of mol/L or M.

Molarity =         mol of solute

                                    L of solution

  The formula for molarity is this:

Percent Concentration

-          Amount of solute dissolved in solvent. It can be computed in two ways; percent by mass and percent by volume.

Percent by Mass

-          One way in representing the concentration of a solution in terms of grams. It can be computed as;

Solubility is the property of a substance (either it’s a solid liquid or gaseous chemical substance) to dissolve and form a homogeneous mixture. This substance dissolved in another substance is called as the solute. And the substance that dissolves a solute to result in a solution is called a solvent.

Double displacement

This reaction takes place when a soluble and insoluble compound reacts w/ each other to yield another substance.

Water (H2O), a gas like CO2 and an insoluble compound form in the product side are the evidence of this reaction.

These reactions are in the general form of :

Single Replacement

-a less reactive metal in a solution has been replaced by a more active metal.

Example: Zn(S) + 2HCl(aq)  ----à ZnCl2 ­+ H2(g)

Understanding the different types of chemical reactions is the key to predict the products of a certain chemical reaction from a given set of reactants. Most reactions fall under four categories; these are combination or synthesis, decomposition, single displacement or single replacement, and double displacement or double replacement. There is also a special type of reaction which is called combustion. But for now, we are going to explore the decomposition chemical reaction.

            In chemistry, chemical synthesis is a purposeful execution of chemical reactions to obtain a product, or several products. This happens by physical and chemical manipulations usually involving one or more reactions. And in modern laboratory usage, this tends to imply that the process is reproducible, reliable, and established to work in multiple laboratories.

            Another term for this reaction is combination reaction. Synthesis reaction is the total opposite of decomposition reaction, why did I say so? Because in synthesis, two or more stable compound is being combined to form one molecule of other compound. While in decomposition, one bulk compound is decomposed into two or more stable compound.

            Aside from the difference of synthesis and decomposition, here is another difference of dehydration synthesis reaction from hydrolysis reaction. In a dehydration synthesis, molecules are bonded together through the loose of water molecules. In hydrolysis, a molecule is broken down by the addition of water.

The elements are written according to their specific symbol and the subscript numbers in the right side of an element/compound indicate how many atoms are present in the given element/compound.

There are many symbols in a chemical equation for example the + sign means that there is another product or another reactant depend where the + sign is located. The + sign is used always as separation between products or reactants and it is usually denote and in a paragraph form equation. For the arrow it is usually denoted as to yield or to produce.

For the physical state it is subscript after the stoichiometric numbers or the element. If a compound or element is in a gas form it is (g), when in liquid (l), when in solid (s), and if aqueous solution (aq). And we can also use other symbols if they are actually used or produce in a chemical reaction.

We need to consider the Diatomic Elements where they have a state of (g) and a subscript number of 2 every time they are individually put in a chemical equation.

Coefficient in the Elements/compounds are the numbers use to balance a chemical equation. Coefficients are used to equalize the number of atoms in the Elements/compounds.

Stoichiometric numbers is the ratio in the elements and compound used in a chemical equation.