Chemistry - Ch. 5 (Yr 10)

Question 1

What is the ‘law of mass of conservation’ ?

Answer 1

Bonds break and reform in chemical reactions but no atoms are destroyed nor created, therefore, the mass remains the same.

Question 2

What does the rearranging of atoms do in terms of mass and products?

Answer 2

The mass stays the same and the products are different from the reactants.

Question 3

What does a ‘catalyst’ do?

Answer 3

It speeds up reactions.

Question 4

The number of atoms in the reactants must be ……. to the amount in the products. (Fill in the gap)

Answer 4

Equal

Question 5

What are the subscripts and their symbols?

Answer 5

S = solid
g= gas
l= liquid
aq = Aqueous

Question 6

What does ‘aqueous’ (aq) mean?

Answer 6

Soluble in water

Question 7

How do you balance an equation?

Answer 7

Count the amount of each element, then add numbers ONLY in front of the elements to make them equal on each side.

Question 8

What is the general equation of a synthesis reaction?

Answer 8

A+B —> AB
The combining/making.

Question 9

What is the general equation of a decomposition reaction?

Answer 9

AB —> A+B
Breaking down

Question 10

What is synthesis?

Answer 10

The forming of compounds by combining simpler elements and substances.

Question 11

What is decomposition?

Answer 11

The breaking down of compounds into their simpler substances.

Question 12

What is the general equation for a neutralisation reaction?

Answer 12

Neutralisation:

acid (pH 1-6) + base (pH 8-14) —> water (pH 7) + salt

Question 13

What ions do acids contain?

Answer 13

Hydrogen ions (H+)

Question 14

What ions do bases contain?

Answer 14

Hydroxide ions (OH-)

Question 15

The reactants ‘Acid + metal oxide’ create a product of?

Answer 15

Salt + water

Question 16

The reactants ‘Acid + metal’ create a product of?

Answer 16

Salt + Hydrogen

Question 17

The reactants ‘Acid + metal carbonate’ create a product of?

Answer 17

Salt + water + carbon dioxide

Question 18

High concentration means? How does this affect an acids ability to give its ions?

Answer 18

High strength.
Strong acids are more readily to give away H+ ions to a base

Question 19

What is ‘precipitate’?

Answer 19

A solid formed by a precipitation reaction which is insoluble in the product.

Question 20

What is the general equation for a single replacement precipitation reaction?

Answer 20

A(aq) + B(aq) —> AB(aq) + C (s)

Question 21

What is a single replacement precipitation reaction?

Answer 21

The rearrangement of elements, isolating a different element.

Question 22

What is the general equation for a double replacement precipitation reaction?

Answer 22

AB(aq) + CD(aq) —> AC(aq) + BD(s)

Question 23

What is a double replacement precipitation reaction?

Answer 23

Rearrangement or elements (swapping pairs), forming one solid in the product.

Question 24

What is a spectator ion?

Answer 24

The soluble products of a reaction, in relation to precipitation reactions.
Eg. AC(aq)

Question 25

What is an oxidation reaction with metal?

Answer 25

Metal + oxygen —> metal oxide

Question 26

What is an oxidation reaction with non metals?

Answer 26

Non metal + oxygen —> non metal oxide

Question 27

What is a general worded equation of a COMPLETE hydrocarbon combustion reaction?

Answer 27

Hydrocarbon + unlimited oxygen —> carbon dioxide + water

Question 28

What is a general worded equation of a IN-COMPLETE hydrocarbon combustion reaction?

Answer 28

Hydrocarbon + limited oxygen —> carbon monoxide + water? Carbon monoxide is a toxic, transparent and odourless gas.

Question 29

What does extremely low oxygen form?

Answer 29

Soot (unburnt carbon) and water

Question 30

What element group from the periodic table don’t react with oxygen?

Answer 30

Group 18

Question 31

What is a polymer?

Answer 31

Polymers are long chains of monomers. Many parts of

Question 32

What are monomers?

Answer 32

Smaller molecules that form polymers

Question 33

What are the three types of polymers?

Answer 33

Linear polymer, cross linked polymer (elastomers), and thermoplastic polymers (plastic).

Question 34

What is the difference between a ‘thermoplastic polymer’ and a ‘thermo setting polymer’?

Answer 34

Thermoplastic: - Malleable when heated Thermo setting polymer: - not malleable (doesn’t melt) - hard, rigid and can go black when hot

Question 35

What must a polymerisation reaction have?

Answer 35

High temperature, pressure and a catalyst

Question 36

What is collision theory?

Answer 36

The colliding of particles/atoms to form a reaction.

Question 37

An increased collision causes an ….. reaction rate. (Fill in gap)

Answer 37

Increased

Question 38

List 4 ways to increase collision?

Answer 38

Surface area, concentration, temperature (kinetic energy), and agitation (stirring)

Question 39

What’s a catalyst?

Answer 39

Increases the rate of a reaction without permanently changing anything

Question 40

How does a catalyst affect activation energy?

Answer 40

They lower the activation energy required for a reaction to occur, making it easier for atoms to break and form chemical bonds.

Question 41

What does a positive catalyst do?

Answer 41

Increase reaction rate

Question 42

What does a negative catalyst do?

Answer 42

Decreases reaction rate