Chemistry

Question 1

Physical Property

Answer 1

characteristics of a substance that can be determined without changing its makeup
- density, lustre, clarity, viscosity, ductility, colour, texture, etc

Question 2

Chemical Property

Answer 2

characteristics determined when the composition of the substance is changed (how it behaves/ reacts)
- reactivity with water, acids, or bases

Question 3

Particle theory

Answer 3

1) all matter is composed of particles.
2) particles are always in motion
3) particles held together by strong attractions (forces)
4) spaces between particles (that are large compared to particles themselves)
5) each substance has a unique particle
6) temperature affects the speed of particles

Question 4

Combining capacity

Answer 4

maximum bonds an atom can make

Question 5

Subatomic particles

Answer 5

neutrons (n), protons (+), electrons (-)

Question 6

Periodic Table

Answer 6

• atomic number = # protons

- mass number = protons + neutrons

Question 7

Define the two different types of ions.

Answer 7

Anion - negatively charged

Cation - positively charged

Question 8

What elements are involved in ionic bonding?

Answer 8

Metals & non-metals

Question 9

Physical change

Answer 9

• does not produce new substance

- usually reversible

Question 10

Chemical change

Answer 10

• produces 1+ new substances

- always irreversible

Question 11

What are some examples of evidence that a chemical change took place?

Answer 11

• change of colour
• precipitate forms in a liquid
• heat or light is absorbed/ produced
• bubbles of gas formed

Question 12

Ionic compound

Answer 12

1+ positively charged metal ion and 1+ negatively charged non-mental ion

Question 13

Explain what happens in an ionic bond.

Answer 13

• atoms trying to attain a full valence shell (octet rule)
• transfer of electron(s) from a metal to a non-metal
• metal becomes ‘isoelectronic’ (or likened) to a noble gas
• the opposite charges of the two atoms binds them together

Question 14

What elements are involved in a covalent compound?

Answer 14

2+ non-metals

Question 15

Diatomic Gases

Answer 15

elements that exist as two atoms together (HOFBrINCl)

Question 16

Explain what happens in a covalent bond.

Answer 16

Both non-metals want to gain electrons, but instead of transferring them they share their valence electrons

Question 17

Reactants

Answer 17

substances that react together in order to form new products

Question 18

Products

Answer 18

new substances made by the chemical RXN

Question 19

List the three equations in which reactions are symbolized in

Answer 19

1) Word
2) Chemical
3) Balanced chemical

Question 20

5 Basic Reactions (use examples)

Answer 20

Synthesis: A + B → AB
Decomposition: AB → A + B
Single Displacement: X + AB → A + XB
Double Displacement: XY + AB → AY + XB
Combustion: Hydrocarbon fuel + oxygen → carbon dioxide + water vapour + energy

Question 21

What is the critical difference between complete and incomplete combustion? Why is it critical?

Answer 21

In complete combustion carbon dioxide, water and energy are the only products. During incomplete combustion, carbon dioxide and carbon are produced as well. Carbon monoxide is deathly because it prevents oxygen flow in the body. Carbon Dioxide is an odourless, colourless gas that latches onto red blood cells.

Question 22

What is the ideal reactant (fuel vs oxygen) ratio to ensure complete combustion?

Answer 22

Fuel needs to rest with an excess of oxygen to ensure complete combustion.

Question 23

Activity Series for Metals

Answer 23

list of metals in order of reactivity/ their likelihood of displacing other metals in reactions (single displacement)
- higher metals can displace lower ones only

Question 24

What are the 4 factors that affect the rate of reaction?

Answer 24

1) Temperature
2) Concentration
3) Surface Area
4) Catalyst

Question 25

What must happen for a reaction to occur?

Answer 25

Particles must come into contact with a certain amount of force and the correct orientation (+/-)

Question 26

Catalyst

Answer 26

• increases rate of RXN but is NOT used up/ altered during it (can be later removed)
• does not become a reactant!
• changes reactants’ orientation to collide more effectively
• ex: fridge delays the rotting process (bio/chem rxns) of mold and bacteria

Question 27

Describe acids

Answer 27

• release H+ ion
• sour
• dissolves well in water
• conducts electricity well
• usually starts with H
• no usual feeling
• ex: vinegar, vitamin C, carbonic acid (aka soda)

Question 28

Describe bases

Answer 28

• release OH- ion
• bitter
• dissolves well in water
• conducts electricity well
• usually has (OH) in it
• slippery
• ex: baking soda, food preservatives, drain cleaner, soap

Question 29

pH Scale

Answer 29

• measures concentration of acids/ bases
• 0 to 14 (acidic = low, basic = high)
• 7 = neutral (water)
• logarithmic; each step is 10x +/- concentrated

Question 30

Neutralization

Answer 30

• adding water = bring pH closer to 7 = diluting

- ACID + BASE → WATER + SALT

Question 31

VSEPR

Answer 31

= Valence Shell Electron Pair Repulsion theory

• electron pair geometry = considers shape of all pairs
• molecular geometry = considers shape of molecule (bonded pairs)

Question 32

Polar Covalent bonds

Answer 32

One atom holdes electrons more strongly than the other (i.e. higher EN)
- 0,5 - 1.7 EN

Question 33

List the different types of VSPER structures

Answer 33

• linear
• triangular planar
• bent
• tetrahedral
• trigonal pyramidal
• angular bent
• triangular bipyramidal
• octahedral

Question 34

Describe how you would draw a diagram of molecules showing bond dipoles.

Answer 34

• element letters
• arrows (+) ⟼ (-)
• δ+ and δ- symbols