chemistry module 1

Question 1

Matter

Answer 1

Anything that takes up space and can be weighed. eg:oxygen

Question 2

all matter is made up of small particles called____?which different states can be distinguished by____?

Answer 2

all matter is made up of smalled particles called ATOMS which different states can be distinguished by their PHYSICAL and CHEMICAL properties

Question 3

state of matter

Answer 3

physical form in which matter can exist,consisting of solid, liquid and gases

Question 4

Compare the bond between solid liquid and gas

Answer 4

Solids have strong bonds, allowing them to stay together
Liquid have weak bonds, allowing them to slide past each other
Gas have no bonds which allow them to fly rapidly around the container as they dont touch(this does not mean that they never touch each other, they do just very rarely)

Question 5

all matters can be classified as what substances?

Answer 5

All matters can be classified as either pure or mix substances

Question 6

Pure substance can be split into what?

Answer 6

elements and compound

Question 7

What is elements

Answer 7

Elements are pure substances that are made of only ONE type of atom. They can appear as singular or in pair
There are 118 known elements in the periodic table (94 naturally occuring and 24 synthetic) Eg: copper, mercury and helium

Question 8

What is compound

Answer 8

Compound consist of TWO OR MORE different types of atoms that are JOINED TOGETHER.
These are puire substances that can only br broken down chemically, not physically as the atoms are chemically bonded together in a fixed ratio, Eg: H2o, sand calcium carbonate

Question 9

what is homogenous

Answer 9

The homogenous mixture contains components that are UNIFORMLY DISTRIBUTED through its volume
Homogenous mixture includes solution that are TRANSPARENT and consist of 2 DIFFERENT PARTS:
- solute: the substances that dissolve in the solution(solvent). Eg; salt
-solvent: the substances that makes the solute dissolve. Eg; water

Question 10

what is heterogeneous

Answer 10

Heterogeneous mixture contains component that are NOT UNIFORMLY DISTRIBUTED through the volume.
Heterogeneous mixture includes suspensions, consisting of an insoluable liquid sunstances. For eg: sand in water is suspension because sand cannot dissolve in water and can be seen seperately.

Question 11

Why cant a mixture be represented by a chemical symbol or chemical formula?

Answer 11

Mixture can’t be represented by a chemical symbol or a chemical formula because it is not chemically bonded and not everyone make their mixture the same.

Question 12

Explain why Earth hydrosphere is considered to be a mixture?

Answer 12

Earth hydrosphere is considered to be a mixture because it is made of different soil and air mixtures

Question 13

What is the different between chemical property and chemical reaction

Answer 13

Chemical property describe how a substance react with other substances to form a new substances(hypothesis on what will happen/describe what could happen.
Whereas, a chemical reaction is when two or more substacnes are change into a new substance . Matter cannot be created or destroyed, it is rearrange at a molecule level. There are signs that cna indicate a chemical reaction(what already happen )

Question 14

What are some example of a chemical reation?

Answer 14

Percipitate: Percipitate is some chemical reactions when you mix two liquids and a solid is formed. The solid that forms called the percipitate, and it may settle at the bottom or make the mixture cloudy. Eg: milk and lemon form cheese when you add it together.
Tempurature change: Chemical reaction can cause energy to be absorbed or released. For eg: adding an antacid tablet to a cup of water will lower the temperature
Gas formation: The production of gas can be a chemical change. Eg: mixing baking soda and vinegar creates carbon dioxide gas that appears as bubbles.
Colour change: Rust on bicycle is formed when oxygen and iron react. A new compound called iron oxide changes the colour of the bike.

Question 15

What is physical property

Answer 15

Physical changes are when a substance changes their form or state but remains the same substance. As no new substances are formed, the change is reversible.

Question 16

what is boiling point

Answer 16

The temperature at which liquid turns into a gas

Question 17

what is melting point

Answer 17

The temperature at which a solid turns into a liquid

Question 18

what is luste

Answer 18

how shiny or dull the substance is

Question 19

size

Answer 19

the size of the particles

Question 20

density

Answer 20

mass of an object within the given volume

Question 21

solubility

Answer 21

the ability of a substance to dissolve in a solvent.

Question 22

Sublimation

Answer 22

when a solid turns directly into a gas without undergoing liquid in between, this happen when particles gain enough energy to break free directly from solid to gas( cause solid have low enerygy they dont move freely)

Question 23

deposition

Answer 23

when a gas changes directly into a solid without undergoing liquid in between, this happen when gas particles lose enough energy and arrange themself into a solid structure ( cause gas has high energy, allowing them to move freely)

Question 24

What causes the particles to move faster when a solid is melting

Answer 24

when hear is applied to the solid making it melt, the particles gained energy which caused them to move faster.

Question 25

What causes the particles to move slower when gas is condensing

Answer 25

When heat is taken away as a result of coldness, the particles loses energy which makes them moves slower, condensing gas to liquid.

Question 26

What is magnetism

Answer 26

Magnetism is used to seperate metal from plastic wave in the mining or recycable industries. Magnets attract certain metal such as iron nickle and steel

Question 27

What is sieving

Answer 27

Sieving seperates a mixture based on the of the components and can be used to seperate solids from liquids or solids from other solids.

Question 28

what is miscibles

Answer 28

Two liquid are miscible if they can mix together and form a single homogeneous solution, eg: water and alcloho

Question 29

what is immiscible

Answer 29

Two liquids are immiscible if they can’t mix together and instead form two separate layers when combined, eg: water and oil.

Question 30

what can you seperate the immiscible liquid by?

Answer 30

You can separate immiscible liquid by using a separating funnel where the two immiscible liquids are separated into different layers based on their density, the stopcock at the bottom allows denser liquid to be collected first.

Question 31

what is distillation?

Answer 31

simple distillation separates miscible liquids through evaporation and condensation due to differences in boiling point.

Question 32

what vaporizes at the lowest temperature and what happen when vapour passes through a condenser

Answer 32

The most volatile(easily evaporates or vaporizes) component vaporises at the lowest temperature, when the vapour passes through a condenser, it condenses back into its liquid state and is collected as a distillate. Different boiling points is essential for the liquid to come out as pure.

Question 33

what is Fractional Distillation

Answer 33

Fractional Distillation is used to separate miscible liquid mixtures containing two or three miscible liquids into their separate parts or fractions using a fractional column.

Question 34

what is decantation

Answer 34

Decantation allows the suspension to separate naturally overtime by pouring or scraping off the top layer of the liquid. A mixture such as clay and water can be separated by leaving it to form a sediment.

Question 35

what is centrifuging

Answer 35

Centrifuging is similar to decantation. However, instead of waiting a long time for the suspension to separate, it uses rapid spinning to apply centrifugal force.

Question 36

what is filtration

Answer 36

Filtration is a technique that separates mixture comprise of particles with varying sizes, some of which are large enough to be captured with a porous material(filter)

Question 37

what is gravity filtration

Answer 37

Gravity filtration uses gravity to pull liquid through the filter.

Question 38

what is suction(vacumn) filtration

Answer 38

suction filtration uses a vacuum to “suck” liquid in the Buchner funnel into the vacuum flask.

Question 39

what is gravimetric analysis:

Answer 39

Gravimetric analysis is a method to measure the amount of substance by weighing it. The process involves separating the substance from a mixture then weighing it to determine how much is present.

Question 40

what is %composition of component and provide example

Answer 40

mass of component/ total mass of mixture * 100 Eg: Calculate the percentage composition of calcium(40g) in calcium oxide(56g) = 40/56 * 100 = 500/7