definitions of laws Flashcards
Avagadros law
equal volumes of gasses at the same temperature and pressure contain equal numbers of molecules (V1 over n1 equals V2 over n2)
Charles law
the volume of an ideal gas at constant temperature is directly proportional to the absolute temperature (V1 over T1 equals V2 over T2)
Boyles Law
the pressure of a given mass of an ideal mass is inverlsley proportional to its volue at a constant temperature (P1V1 equals P2V2)
Conservation of Mass
in a chemical equasion mass is neither created nor destroyed
Gay-Lussecs Law
the ratios between volumes of the gaseous reactants and the products can be expressed in simple whole numbers (P1 over T1 equals P2 over T2)
Week 4
COMBUSTION
Definition: Burning or the rapid combination of a substance (e.g. hydrocarbons) with oxygen
Word equation:
Fuel + oxygen → carbon dioxide + water
(fuel could be a hydrocarbon like glucose which is respiration, could be alcohol, alcane)
Week 4
OXIDATION
Definition: Chemical reaction in which oxygen is added to a substance or hydrogen is removed from a substance. Any reaction when a material loses electrons
Word equation:
Magnesium + oxygen → Magnesium oxide
Week 4
ACIDS ON METALS
Word equation: Acid + metal → salt + hydrogen
2Hcl + Mg → MgCl2 + H2
H+ Mg.. Mg 2+
MAGNESIUM is above hydrogen on the scale so it oxidises
Week 4
ACIDS ON CARBONATES
Word equation:
acid + carbonate → salt + water + carbon dioxide
HCl + CaCO3 → CaCl2 + CO2 + H2O
Copper, silver, platinum and gold do NOT react with acids as they are below hydrogen
Week 4
NEUTRALISATION
Definition: Reaction of an acid with a base to form a salt and water
Word equation: Acid + base → salt + water
H+ + OH- → H2O must know this
NaOH + HCl → H2O and NaCl
Week 4
DECOMPOSITION
Definition: Reaction where one substance breaks down into simpler substances.
Word equation:
Metal oxide metal + oxygen or
metal carbonate → (heat) metal oxide + carbon dioxide
Thermal decomposition→ is a decomposition reaction that requires heat to break down the compound.
Metal carbonates undergo thermal decomposition
Week 4
RESPIRATION
Definition: a chemical reaction that goes on inside the cells of living things that break down glucose using oxygen to produce carbon dioxide, water and energy. Sim ilar to combustion but much slower and does not release light
Week 4
COMBINATION
Combination reactions occur when two reactants combine to form a single product
General Equation:
A+B → AB
Week 4
PRECIPITATION (ionic exchange)
Definition: The formation of a solid when two solutions are mixed
Word equation: Lead (II) nitrate + potassium iodide → lead (II) iodide(s) + potassium nitrate
Week 4
SYNTHESIS
Definition: The combining of reactants to make products
Word equation:
sodium + chlorine → sodium chloride
