chemistry chapter 1

What is the particle arrangement/movement for solids?

In solids, particles are closely packed together in a fixed arrangement and vibrate in place. This results in a definite shape and volume.

what is the particle arrangement/movement for liquids?

In liquids, particles are close together but can move past one another, allowing liquids to take the shape of their container while maintaining a fixed volume.

what is the particle arrangement/movement for gases?

In gases, particles are far apart and move freely at high speeds, resulting in no fixed shape or volume, allowing gases to expand to fill their container.

What is the melting point?

The melting point is the temperature at which a solid turns into a liquid, where the particles gain enough energy to overcome their fixed arrangement and begin to move freely.

what is the boiling point?

The boiling point is the temperature at which a liquid turns into a gas, where the particles gain sufficient energy to break free from the liquid's surface and enter the gas phase.

what happens when you heat up a gas?

When you heat up a gas, its particles gain energy, move faster, and the gas expands. This can lead to an increase in pressure if the gas is in a confined space.

what happens when you cool a liquid?

When you cool a liquid, its particles lose energy, move slower, and begin to come closer together. This process may eventually lead to the liquid freezing and transitioning into a solid state.

what happens when you cool a gas?

When you cool a gas, its particles lose energy, move slower, and come closer together. This process may eventually lead to the gas condensing into a liquid state.

why is the particle model not perfect?

Particles are not solid, inelastic, or spheres

state symbols for solid, liquid, gas, aqeuous in order

s, l,g, aq

what is solute

the thing that is dissolved

what is solvent

the thing the solute is dissolved in

what is a solution

when the solute is dissolved in the solvent

what is a saturated solution?

a solution that has the max amount of solute dissolved in the solvent.

what is solubility

the meausement of how much solute can dissolve in a solvent. measured in g/cm³

what is an atom

the smallest thing possible.

what are the subatomic particles of an atom?

proton, neutron, electron

where do the electrons orbit?

in shells around the nucleus.

what is the relative mass of each of the subatomic particles?

proton - 1, neutron - 1, electron - 1/2000 or close to 0.

what is the charge of an atom

neutral.

what is an ion?

when atoms lose/gain electrons.

What happens when an atom gains an electron? Loses and electron?

it becomes a 1- ion 2) becomes a 1+ ion.

what are the components of the nuclear symbol?

has the mass number at the top (which is the number of protons and neutrons in the atom - the nucleus) and the atomic number at the bottom (the number of protons) and the symbol of the element.

what determines the element? What does this mean for electrons?

the number of protons - this means that an atom can have a different number of electrons but still be the same element, but if the number of protons changes, the element changes.

what is an isotope

an atom with the same number of protons but different number of neutrons.

what happens to the mass/atomic number if it forms a heavier isotope?

the mass number will increase as the number of neutrons increases, and so will the weight of the nucleus, but the atomic number will stay the same as the number of protons has not changed.

formula for RAM?

sum of (isotope abundance * isotope mass)/sum of abundance of isotopes

what is isotope abundance?

percentage of all of the element that isotope makes up.

what is a molecule?

a group of 2 or more atoms chemically bonded

what is a compound?

2 or more different elements chemically bonded.

what is a mixture?

2 or more substances not chemically bonded.

what is filtration?

used to separate 2 insoluble substances.

how do you do filtration?

You get filter paper and put it in a funnel, then get a beaker to collect the filtrate in. Then pour the mixture into the filter paper and wait for all to come through.

how do you do evapouration?

put your solution into an evapourating dish on top of a gauze, on top of a trippod. Get a bunsen burner and heat solution slowly. solvent will evapourate, leaving behind solute.

what are the advantages/disadvantages of evapouration?

it is quick and easy however some solids will decompose when heated and will change into something else. You cannot collect the solvent, as it has evapourated.

how to do crystallisation?

put into an evapourating dish in a water bath and heat. When it starts to crystallise, stop heating. leave to cool. Filter out. dry crystals by leaving somewhere warm.

Why do you leave it to cool in crystallisation?

solids are less soluble at colder temperatures.

what is chromatography?

separating different substances in a mixture by solubility.

how to do chromatography.

add sample of ink to line made of pencil. (on filter paper) put filter paper in a beaker of a small amount of solvent. don’t let it touch baseline. wait for dyes to travel up paper. When it has nearly travelled to the top, leave it to dry.

what is a chromatogram?

the things that the filter paper tells us when cooled after chromatography.

What does a dot that moved up further mean?

it is more soluble.

what does a dot sitting on the baseline mean?

it is not soluble.

what does it mean if a substance makes multiple dots?

it is a mixture and each substance is a different chemical.

what is the mobile phase?

solvent.

what is the stationary phase?

the filter paper.

What does the mixture do when moving up paper?

move between the mobile and stationary phase, switching between dissolving in the solvent and moving up the paper.

equation for Rf value.

distance travelled of solute/distance travelled of solvent.

what does substances that travelled the same distance mean?

they are the same substance or contain that substance.

how to do simple distillation?

set up equipment (flask containing solution with a thermometer and bung in it, connected to a condensing tube filled with a continuous flow of cool water, and a beaker at the end to collect the solution left behind) heat mixture so solution evapourates. pressure will force it down condenser. vapour will cool and consdense into liquid form. it will collect in beaker.

how to do fractional distillation?

heat at the point of the substance with the lowest melting point. that chemical rises. it then goes through condenser. repeat until you separate all chemicals in mixture.

what is in the fractionating column

filled with little glass rods which increases surface area, cooler at top than bottom.

what does the fractionating column do?

if by chance the other chemical has evapourated, it will travel up the tube and then turn back to liquid and come back down back into the solution.

what is fractional distillation for?

used for separating mixture with similar boiling points of substances.