particulate nature of matter đĒŠ Flashcards
state kinetic particle theory
all matter is made up of numerous tiny particles in constant, random motion
describe what happens during melting / boiling
forces of attraction between particles are overcome and particles move further apart. particles now slide over one another / move at high speeds in constant, random motion
why is there no gain in temperature during melting / boiling?
all energy is used to overcome forces of attraction between particles
describe what happens during freezing / condensation
forces of attraction between particles become stronger and particles move closer to one another. particles now vibrate about fixed positions / slide over one another easily
why is there no loss in temperature during freezing / condensation?
heart removed during cooling is equal to heat released by particles when taking up more orderly arrangement
why is there no loss in temperature during freezing / condensation?
heart removed during cooling is equal to heat released by particles when taking up more orderly arrangement
observation of diffusion of gases (bromine and oxygen in a jar)
brown bromine gas spread upwards until a brown colouration is seen throughout the gas jars over a period of time
explanation for diffusion of gas (bromine and oxygen in a jar)
both bromine gas and oxygen gas are made up of numerous tiny particles moving in constant, random motion. bromine particles diffuse into the space between oxygen particles and vice versa
how does Mr affect rate of diffusion?
lower Mr = faster rate of diffusion
explanation for Mr effect on diffusion (porous pot)
the relative molecular mass of hydrogen, 2.0, is lower than the relative molecular mass of air, 29.0. thus, hydrogen gas diffuses into the porous pot faster than air can diffuse out. this increases the pressure in the porous pot, causing water level to fall initially
