Module 3: Reactive Chemistry Flashcards
hydroxide
OH-
Nitrate
NO3 (-1)
Nitrite
NO2 (-)
Phosphate
PO4-3
Sulfate
SO4-2
Sulfite
SO3 (-2)
Carbonate
CO3 (-2)
ammonium
NH4 +
what is a physical change?
a type of change in which the form of matter is altered but one substance is not transformed into another.
What is a chemical change?
Chemical Changes occur when a new substance is formed and hence is called a chemical reaction
Physical change examples:
Melting Ice, boiling water, chopping wood
Chemical change examples:
Burning Wood, fireworks, cooking an egg`
Boiling of water versus electrolysis of water:
Boiling water= physical change as its particles remain the same. Electrolysis is a chemical change as it involves energy to remove separate hydrogen and oxygen molecules.
Indicators of a chemical change:
color change, formation of a precipitate, formation of a gas, odor change, temperature change
Model of chemical changes experiment:
-aim
Aim: To model what occurs at the atomic level during chemical reactions while ensuring that the law of conservation of mass applies
Model of chemical changes experiment:
-identify what occurred and why was it helpful
Identify- Modelling how bonds in chemical reactions are broken/formed
Describe: lollies= chemical and toothpicks= bonds
Explain: Chemicals + bonds/ reactions are too small to see, so models are used to teach a concept
what is a synthesis reaction?
A synthesis reaction involves the formation of a compound from its elements or from other, usually smaller, compounds.
Magenisum + Oxygen=
magnesium oxide
synthesis reaction
A non-metal oxide + water =
an acid
A metal oxide + water =
base
what is a decomposion reaction?
A decomposition reaction involves a single REACTANT breaking down to form a simple product. It usually involves energy from an external source (thermal or electrical)
Metal nitrate =
Metal nitrate + oxygen
decomposition
What is the Important example of a decomposition reaction?
electrolysis of water
metal carbonate=
metal oxide + Carbon dioxide
metal hydroxide =
metal oxide + water
What is ahydrocarbon?
Hydrocarbons (petrol, oil, coal, gas) contain hydrogen and carbon, because of this they make good fuels as energy is released when the bonds are broken following chemical reactions.
methane:
CH14
propane:
C3H8
ethane:
C2H6
Butane:
C4H10
Betane:
C5H12
What is complete combustion?
Hydrocarbons all burn in sufficient air or oxygen to produce carbon dioxide and water. Combustion is an exothermic chemical reaction. There is no net release of energy.
What is incomplete combustion?
Combustion requires oxygen, however in a low oxygen environment combustion can still occur but the products may be different. Carbon monoxide or soot (carbon) can result.
When does a precipitate form?
when the attraction between two oppositely charged ions is greater than the attraction between the individual ion and the water molecules. In this case, the oppositely charged ions will bond ionically to each other and precipitate out of the solution as an insoluble solid.
What is double displacement?
reactions occur when two elements in different compounds trade places:
What are the solubility rules?
-Soluble
- Group 1 + NH4+ compounds
- Nitrates
- chlorides ( except Ag+ and Pb2+)
- Sulfates ( except Ag+, Pb2+, Ba2+Sr2+, Ca2+)
What are the solubility rules?
-Insoluble
Carbonates (except group 1 and NH4+)
Hydroxides and oxides (except group 1, Nh4+ , Ba2+Sr2+, Ca2+)
Whats the difference between soluble and insoluble?
Soluble fiber dissolves in water, and Insoluble fiber doesn’t dissolve in water.
Whats an acid?
substance that in solution produces H+ ions
What are acids properties?
Taste sour, conduct electricity in solution , Ph < 7
What’s a base?
substance that in solution produces OH- ions
what are base properties?
feels slippery, tastes bitter, conducts electricity in solution, PH > 7