chemistry
What is a diatomic molecule
molecules compised of only two atoms of the same element (HOFBrINCl)
law of conservation of mass
Matter is neither created or destroyed, and in any chemical reaction the total mass of the reactants must be equal to the total mass of the products
synthesis
two simple reactants combine to form a larger or more complex product (A + B = AB)
e.g sodium + chlorine gas = sodium chloride
decomposition
a complex reactant breaks down to make two or more simpler products (AB = A + B)
single displacement
a non- metal may displace another non metal from a compound (AB + C = AC + B)
a metal may displace another metal or hydrogen from acids or water (AB + E = EB + A)
double displacement
two compounds react to form two new compounds
AB + CB = AD + CB
combustion
the reaction of carbon with oxygen, if carbon monoxide or soot is formed it is incomplete combustion
acids
ionize to produce hydrogen ions in a solution (forming ions from a covalent bond)
Oxoacids fo when hydrogen combines with a polyatomic ion that contains oxygen
Binary acids form when hydrogen combines with a non metal, usually a halogen
bases
form when a metal combines with the polyatomic ion hydroxide (OH-)
they break down when dissolved in water to produce positive metal ions and negative hydroxide ions
acids properties
sour, no specific texture, conductive, corrodes tissues and metals, makes hydrogen gas when reacting with metal, turns blue litmus red, colourless ph, 0-7
bases properties
bitter, slippery, conductive, corrodes only tissues, no reaction with metal, turns red litmus blue, pink with phenolpthalein, 7-14 ph range
acid base indicator
changes colour depending on if its an acid or base, phenolpthalein, litmus paper, and cabbage juice
neutralization reactions
the number of hydrogen ions and hydroxide ions must be the same to be neutral. Balance acids and bases to make them neutral, this is a double displacement reaction
ionic vs molecular
Ionic: Metal with non metal
Molecular: non metal with non metal, share electrons
pH scale
the measure of how acidic or basic a solution is, 7 is neutral. Below seven is more acidic, and above seven is more basic
Alkali metals
first group, soft, shiny, silvery and reactive with water
alkaline earth metals
shiny but not as soft as first group, burn with colourful flames
halogens
very reactive gases
chemical change indicators
change in colour, change of odour, gas bubbles, precipitate formed, heat or light is released
conservation of mass law
matter is neither created or destroyed
in any chemical reaction the total mass of reactants is equal to total mass of products