Unit 4 Matter, Chemical reactions, Separation of Mixtures

Question 1

States of matter + Properties + Kinetic theory of matter

Answer 1

Solid:
1) Fixed volume and shape with high density.
2) Atoms vibrate in position but can’t change location.
3) Particles are packed very closely together in a fixed and regular pattern.
4) Low energy

Liquids:
1) Fixed volume but adopt the shape of the container.
2) Less dense than solids but more dense than gases.
3) Liquid adapts to the shape of the container because Particles move and slide past each other.
4) Greater energy compared to solids.

Gases:
1) No fixed volume or shape, adopt the shape of the container.
2) Very low density.
3) Particles are far apart and move randomly and quickly.
4) They collide with each other and the container sides creating pressure.
5) Highest energy.

Kinetic theory of matter:
The differences in the physical properties between states are because of the arrangement and motion of particles.

Question 2

Diffusion

Answer 2

The movement of molecules from high concentration to low concentration until the concentration of particles is even.

Faster in gases than liquids,
Faster in high temperatures,
Faster in low molecular masses,

No energy is needed.

Question 3

Brownian motion

Answer 3

The random movement of small particles surrounded by a fluid, due to the collision with the particles of the fluid.

Question 4

Separation of Mixtures:
Magnetic Separation, and Paper Chromatography

Answer 4

Magnetic Separation: Using a magnet to pick up metal objects from non-metals.

Chromatography: A method for separating mixtures where a small dot of the mixture is placed on paper and allowed to be pulled up by a liquid (solvent).
Different parts of the mixture move up the paper at different speeds stopping at different points.

Question 5

Separation of Mixtures:
Filtration, Evaporation, simple and fractional Distillation

Answer 5

Filtration: passing a mixture through a barrier that catches the solid parts while letting the liquid or gas flow through.

Evaporation: Allowing the solvent to vaporize and leave behind the solute.

Simple Distillation: Heating the mixture to turn one part into vapor, then cooling it down to turn it back into liquid, leaving behind the other part. boiling points with a gap of a minimum of 50 degrees.

Fractional Distillation: Same as S.D but with substances with close Boiling Points. Eg: fractional distillation of crude oils to separate the oil into useful fractions like kerosene, petrol, diesel,
etc.

Question 6

Chemical Reactions 5 types

Answer 6

Synthesis reaction: When 2 or more simpler substances combine to form a more complex substance.
eg: 2H2+O2 → 2H2O

Decomposition reaction: When a compound breaks down into simpler substances.
eg: 2H2O → 2H2+O2

Single Replacement reaction:
When 1 element replaces another element in a compound.
eg: Zn+2HCl → ZnCl 2+H2
​
Double Replacement reaction:
When parts of 2 compounds switch places to form 2 new compounds.
eg: NaCl+AgNO3 → AgCl+NaNO3
Sodium chloride reacts with silver nitrate to form silver chloride and sodium nitrate.

Combustion: when a substance reacts rapidly with oxygen gas (O2) to produce heat and light.
eg: CH4+2O2 → CO2+2H2O

Question 7

Explain the Kinetic theory and State change: Melting, Boiling, and Evaporation

Answer 7

All matter is made of atoms, which are in continuous motion. motion needs kinetic energy which is gained from heat energy.
So basically if we heat a solid causes it’s particles to vibrate until the solid expands, the structure breaks, and then melts.

Melting: Solid→ Liquid
heat energy is turned to Kinetic energy allowing the particles to move. Melting point of H2O = 0C

Boiling: Liquid→ Gas
Boiling point of H2O = 100C

Evaporation: Liquid→ Gas at the surface. At temperatures below its boiling point.

Question 8

State change: Condensation, Freezing, Sublimation, and desublimation

Answer 8

Condensation: Gas→liquid
When gas is cooled its particles lose energy and when they bump into each other they lack the energy to bounce instead, they group forming liquid.

Freezing: Liquid→ Solid
reverse of melting, occurs at the same temp. 0C

Sublimation: Solid→ Gas
Happens to a few solids like Iodine.
Desublimation or deposition is the opposite reaction

Question 9

Heating and cooling curves

Answer 9

https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.worldwisetutoring.com%2Fheating-and-cooling-curves%2F&psig=AOvVaw1I7l3lO2AUKTbtG8knYuqy&ust=1713790755053000&source=images&cd=vfe&opi=89978449&ved=0CBIQjRxqFwoTCPjl1pqu04UDFQAAAAAdAAAAABAE

Question 10

Pressure and temperature relation in gases

Answer 10

As temperature increases the volume will increase.
Pressure increases as volume decreases.