Chemistry As

Question 1

What happens to equilibrium when pressure is lowered?

Answer 1

Equilibrium shifts to the side with most gas molecules.

Question 2

How does decreasing reactant concentration affect equilibrium?

Answer 2

Equilibrium moves to the reactant side.

Question 3

How does increasing product concentration affect equilibrium?

Answer 3

Equilibrium moves to the reactant side.

Question 4

What is the effect of increasing reactant concentration on equilibrium?

Answer 4

Equilibrium shifts to the product side.

Question 5

What is the role of a catalyst in a chemical reaction?

Answer 5

Increases the rate at which equilibrium is reached without affecting the equilibrium position.

Question 6

Fill in the blank: Oxidising Agents are ________ and Reducing Agents are ________.

Answer 6

Electron Acceptors; Electron Donors.

Question 7

What is the chemical equation for the Haber Process?

Answer 7

N2 + 3H2 = 2NH3 (g) [Exothermic]

Question 8

What are the reactants in the Haber Process?

Answer 8

• Nitrogen: From the air
• Hydrogen: From the reaction between Methane and Steam

Question 9

What are the conditions used in the Haber Process?

Answer 9

• Temperature: 450°C
• Pressure: 200 atm (20,000 Pa)
• Catalyst: Iron catalyst

Question 10

Why is pressure not extremely high in the Haber Process?

Answer 10

Higher pressure increases yield but requires more expensive equipment and can be dangerous.

Question 11

What is the chemical equation for the Contact Process?

Answer 11

SO2 + O2 = 2SO3 (g) [Exothermic]

Question 12

What are the reactants in the Contact Process?

Answer 12

• Sulfur Dioxide: Burning sulfur or Roasting Sulfide ores
• Oxygen: From the air

Question 13

What are the conditions used in the Contact Process?

Answer 13

• Temperature: 450°C
• Pressure: 2 atm (200 kPa)
• Catalyst: Vanadium (V) oxide catalyst

Question 14

Why is pressure kept high in the Contact Process?

Answer 14

Higher pressure increases yield.

Question 15

Define Redox.

Answer 15

A simultaneous oxidation and reduction reaction.

Question 16

What is oxidation in terms of electron movement?

Answer 16

Loss of electrons.

Question 17

What is reduction in terms of electron movement?

Answer 17

Gain of electrons.

Question 18

What indicates the oxidation state in a reaction?

Answer 18

The oxidation state highlights electron movement.

Question 19

In the reaction CuO + Mg -> MgO + Cu, what happens to Copper?

Answer 19

Copper (II) is reduced.

Question 20

In the reaction CuO + Mg -> MgO + Cu, what happens to Magnesium?

Answer 20

Magnesium is oxidized.

Question 21

What happens to Acidified Aqueous Potassium manganate (VII) when it acts as an oxidising agent?

Answer 21

Changes from purple to colourless.

Question 22

What happens to Aqueous Potassium iodide when it acts as a reducing agent?

Answer 22

Changes from colourless to yellow-brown.

Question 23

What is the oxidation number of an element in its uncombined state?

Answer 23

Zero.

Question 24

What is the oxidation number of a monatomic ion?

Answer 24

The same as the charge of the ion.

Question 25

What is the sum of the oxidation numbers in a compound?

Answer 25

Zero.

Question 26

In the ion MnO4-, what is the oxidation number of Mn?

Answer 26

+7.

Question 27

What is the behavior of weak alkalis in water?

Answer 27

Partially ionize, producing OH- ions.

Question 28

What is an element?

Answer 28

A substance made of atoms that share the SAME number of protons and cannot be broken down into simpler substances by chemical methods.

Question 29

How many elements are in the periodic table?

Answer 29

There are 118 elements in the periodic table.

Question 30

What is a compound?

Answer 30

Two or more elements chemically bonded together (in a fixed proportion). ## Footnote Example: Carbon Dioxide, Sodium Chloride

Question 31

What is a mixture?

Answer 31

Two or more elements not chemically bonded together. ## Footnote Example: Sand and Water, Oil and Water

Question 32

What are atoms?

Answer 32

Tiny particles that are the building blocks of all matter.

Question 33

What is the structure of an atom?

Answer 33

It has a central nucleus containing neutrons and protons, surrounded by electrons.

Question 34

What are the characteristics of protons, neutrons, and electrons?

Answer 34

Protons have a relative mass of 1, neutrons have a relative mass of 1, and electrons have a relative mass of 1/1840.

Question 35

What is the overall charge of an atom?

Answer 35

Neutral, because electrons and protons have opposing and equal charges.

Question 36

What is the Proton Number (Atomic Number)?

Answer 36

The number of protons in the nucleus of an atom, denoted by the letter 'Z'.

Question 37

What is the Nucleon Number (Mass Number)?

Answer 37

The total number of protons and neutrons in the nucleus of an atom.

Question 38

How is the Mass Number calculated?

Answer 38

Mass number = number of protons + number of neutrons.

Question 39

What is the AZX Notation?

Answer 39

A format showing Mass Number, Symbol of the element, Atomic Number, and Atomic Mass.

Question 40

What are electron shells?

Answer 40

Orbits around a central nucleus where electrons reside.

Question 41

What is the maximum capacity of the first electron shell?

Answer 41

The first shell has a maximum capacity of 2 electrons.

Question 42

What is the general complete electronic configuration for this syllabus?

Answer 42

(2.8.8)

Question 43

What are isotopes?

Answer 43

Different atoms of the same element with the same number of protons but different numbers of neutrons.

Question 44

Do isotopes have the same chemical properties?

Answer 44

Yes, they have the same number of outer shell electrons and the same electronic configuration.

Question 45

How do isotopes differ in physical properties?

Answer 45

The difference in mass affects properties such as density, boiling point, and melting point.

Question 46

What is malleability?

Answer 46

The ability to be hammered into shapes as layers.