~ A chemical reaction has not occurred if the products have the same chemical properties as the reactants.
~ Formation of a precipitate, evolution of heat and light, or production of a gas will indicate that a reaction has occurred
~ A solid produced by a chemical reaction in a solution that separates from the solution is called a precipitate
~ 2(CO)(g)+O(g)------>2Co2+energy is an exothermic reaction because the bond energies of CO and O2 are higher than bond energy CO2.
~C2H5OH is called ethanol
~Non-spontaneous reactions can occur when energy is added.
~The reaction C2H5OH+3O2------> 2CO2 + 3H2O will occur most rapidly if C2H5OH and O2 are in close contact
~After the correct formula for a reactant in an equation has been written, the formula should not be changed.
~To balance a chemical equation, it may be necessary to adjust the coefficents.
~In writing an equation for a reaction that produces hydrogen gas, the correct representation of hydrogen gas is H2.
~When sodium chlorate, NaClO3, decomposes the products are sodium chloride and oxygen.
~Chlorine gas is produced by halogen displacement, the other halogen in the reaction must be fluorine (most active).
~ The formulas for the products of the reaction between sodium hydroxide and sulfuric acid are Na2So4 and H2O
~ Q: What is the balanced equation when aluminum reacts with copper (II) sulfate?
A: 2Al+3CuSO4 ---> Al2(SO4)3 + 3Cu
~According to the law of conservation of mass, the total mass of the reacting substances is always equal to the total mass of the products.
~ A chemical reaction is balanced when the same number of each kind of atom appears in the reaction and in the products.
~After the first steps in writing an equation, the equation is balanced by adjusting coefficents to the smallest whole number ratio.
~ The complete balanced equation for the reaction between zinc hydroxide and acetic acid: Zn(OH)2 + 2CH3COOH---> Zn(CH3COOH)2 +2H2O
~ The balanced equation for the combustion of sulfur is S(s) + O2 ------> SO2 (g)
~A coefficient is the small whole number ratio that appears in front of a formula in a chemical reaction.