3.1 - Introduction Flashcards
what are physical changes
-creates no new substances
- usually easy to reverse
-absorb or release small amounts of energy
what are chemical changes
- create new substances
- usually difficult to reverse
-absorb or release large amounts of energy
what is a chemical test for pure water
anhydrous copper sulfate turns blue to white
what is a physical test for pure water
when the boiling point is 100 degrees C
(when the melting point is 0 degrees C)
what is an element
a substance containing only one type of atom
what are metal properties
high MP/BP
electrical conductors
malleable
shiny
what are non-metal properties
low MP/BP
electrical insulators
brittle
dull
what side of the PT are metals on
left
what side of the PT are non-metals on
right
what are the diatomic elements
hydrogen = H2
nitrogen = N2
oxygen = O2
fluorine = F2
chlorine = Cl2
bromine = Br2
iodine = I2
astatine = At2
how can you recognise the diatomic elements
form an upside down L on the periodic table and hydrogen
what is a compound
a substance containing more than one type of atom, chemically bonded together
how can compounds often be formed
by heating elements together
what is interesting about the properties of compounds
they are totally different from the properties of the elements the compound is made from
what are the three types of bonding in compounds
metallic
ionic
covalent
what is the bonding of a metal and a metal
metallic
what is the bonding of a metal and a non-metal
ionic
what is the bonding of a non-metal and non-metal
covalent
what experiment is used to illustrate the diffusion of gases
making the compound ammonium chloride in a tube
what is the word equation for the ammonium chloride tube experiment
ammonia + hydrogen chloride –> ammonium chloride
what does the ammonium chloride experiment show about the weight of the molecules
hydrogen chloride is heavier because it diffused slower
what happens if you heat up the tube in the ammonium chloride experiemnt
the white smoke forms faster because the particles move fatser and collide more often - it still forms in the same place because both gases diffuse faster
what is a solute
the substance which is going to be dissolved
what is a solvent
the liquid which is going to do the dissolving
what is a solution
the resulting mixture of a solute dissolved in solvent
what is saturates
a solution in which no more solute can be dissolved
what is suspension
a solid floating in a liquid because it cannot dissolve
what is soluble
a substance which can be dissolved
what is insoluble
a substance which cannot be dissolved
what do you measure solubility in
g per 100g of solvent
what does solubility vary with
temperature
what are the three parts of a solubility curve
the line = saturated
below = soluble
above = insoluble
what does the line show
saturated
the maximum mass of solid which can be dissolved at each temperature
what does the space below the line show
soluble
less than the maximum mass of solid so it will all dissolve
what does the space above the line show
insoluble
more than the maximum mass of solid so some will dissolve and some won’t
where can the mass that dissolves be found on a solubility graph
reading off the line
