physivs Flashcards
what is an exothermic reaction
it is a reaction that releases heat energy an example of this is magnesium + copper
what is an endothermic reaction
it is a rection that takes in heat energy (heat will rise)
what is a physical change
a change that is reversable, new substances are not made ex: boiling
what is a chemical change
a change in which atoms are re- arranged to create new substances, usually irreversible
what are the signs of a chemical change
fizzing, colour changes, energy changes, temperature or light emitting, an odour and/or a precipitate forming
what does the conservation of mass state
it states that the mass of the reactant should equal that of the product ex: C+2eL=cCL4
what is combustion
combustion is burning in air
name the three components required to create the fire triangle
oxygen fuel and heat are required
what is a precipitation reaction
it is one in which substances in a solution are mixed and or an insoluble product is made. the insoluble product is called the precipitate this can also happen if you change the solubility of a solute by changing the temperature of the reaction.
name the precipitate in these three word equations
- potassium chloride + silver nitrate
- potassium bromide + silver nitrate
- potassium iodide + silver nitrate
- silver chloride
- silver bromide
- silver iodide
name the solution in these three word equations
- potassium chloride + silver nitrate
- potassium bromide + silver nitrate
- potassium iodide + silver nitrate
- potassium nitrate
- potassium nitrate
- potassium nitrate
what does hydrochloric acid+ sodium hydroxide=
sodium chloride+ water
what are the salts that can be formed from an acid + alkali
hydrochloric acid-chloride
sulphuric acid-sulphate
nitric acid-nitrate
what are the ways of breaking something down/ decomposing
electrosis
thermal decomposition
photolysis
micro organisms
what is the test for carbon dioxide
it is turning lime water cloudy or lime water turning cloudy
