4.1

Question 1

Q: What are the Group 1 metals known as, and how do they react with water?

Answer 1

A: The Group 1 metals are known as the alkali metals. They form alkaline solutions when they react with water.

Question 2

: Name the Group 1 metals and their characteristics.

Answer 2

Alithium, sodium, potassium, rubidium, caesium, and francium.
They share similar characteristic properties because they each have one electron in their outermost shell.
being soft metals, having relatively low densities and low melting points, and being very reactive

Question 3

Q: Where are the alkali metals located in the periodic table?

Answer 3

A: The alkali metals are located on the far left of the periodic table, in the very first group.

Question 4

Q: Describe the trends and properties of Group 1 metals.

Answer 4

A: The alkali metals are soft and easy to cut, getting softer as you move down the group. Potassium is an exception, having a lower density than sodium. The first three alkali metals are less dense than water. They all have relatively low melting points which decrease as you move down the group due to decreasing attractive forces between outer electrons and positive ions.

Question 5

Q: How does the melting point of Group 1 metals change as you descend the group?

Answer 5

A: The melting point of the Group 1 metals decreases as you descend the group.

Question 6

Q: Explain the trend in reactivity of Group 1 metals.

Answer 6

A: The reactivity of the Group 1 metals increases as you go down the group. As you descend the group, the outermost electron gets further away from the nucleus, leading to weaker forces of attraction between the outermost electron and the nucleus. This makes it easier for the outer electron to be lost, resulting in increased reactivity

Question 7

Q: Describe the reactions of the first three alkali metals with water.

Answer 7

A: The alkali metals react with water to form metal hydroxides and hydrogen gas
reactivity of these reactions increases as you descend the group.
lithium reacts slowly with water to form lithium hydroxide and hydrogen gas,
sodium reacts more vigorously,
and potassium reacts explosively.

Question 8

Reaction Equations for the first three alkali metals with water

Answer 8

Lithium + water —> Lithium Hydroxide + Hydrogen
2Li + 2H2O —> 2LiOH + H2

same with sodium and potassium

Question 9

Q: Explain why alkali metals are usually stored in oil.

Answer 9

A: Alkali metals react readily with oxygen and water vapor in the air, so they are usually stored in oil to prevent them from reacting.

Question 10

Q: Describe the reactions of the first three alkali metals with oxygen.

Answer 10

A: The alkali metals react with oxygen in the air to form metal oxides, resulting in the tarnishing of the metal surfaces. The metal oxides produced form a dull coating over the metal surface.

Question 11

Reaction Equations for first three alkalis metals with oxygen

Answer 11

“alkali metal” + Oxygen —> “alkali metal” oxide
4”metal” + O2 —> 2 “metal”2 O

Question 12

Q: Describe the reactions of the first three alkali metals with chlorine.

Answer 12

A: All the Group 1 metals react vigorously when heated with chlorine gas to form salts called metal chlorides. This reaction becomes more vigorous as you move down the group.

Question 13

Reaction equations for the first three alkali metals with chlorine

Answer 13

“metal” + Chlorine → “metal” Chloride
2”metal” + Cl2 —> 2”metal”Cl

Question 14

Q: What are the elements in Group 7 known as?

Answer 14

A: The elements in Group 7 are known as the halogens.

Question 15

Q: Name the halogens.

Answer 15

A: The halogens are fluorine, chlorine, bromine, iodine, and astatine

Question 16

Q: Describe the general characteristics of halogens.

Answer 16

non-metals that are poisonous.
They all have similar reactions as they each have seven electrons in their outermost shell.
Halogens are diatomic, meaning they form molecules made of pairs of atoms sharing electrons, resulting in a single covalent bond between the two halogen atoms.
When halogen atoms gain an electron during reactions, they form -1 ions called halide ions.

Question 17

Explain the trend in melting and boiling points of halogens down the group.

Answer 17

A: The melting and boiling points of the halogens increase as you go down the group. This is due to increasing intermolecular forces as the atoms become larger, requiring more energy to overcome these forces

Question 18

Q: Describe the physical states of halogens at room temperature and their colors.

Answer 18

A: At room temperature (20 °C), the physical states of the halogens change as you go down the group. Fluorine and chlorine are gases, bromine is a liquid, and iodine is a crumbly solid. The colors of the halogens also change as you descend the group, becoming darker.

Question 19

Q: How does the reactivity of Group 7 non-metals change as you descend the group?

Answer 19

A: The reactivity of Group 7 non-metals decreases as you go down the group.

Question 20

Q: Explain the relationship between electron shells and halogen reactivity.

Answer 20

A: As you go down Group 7, the number of electron shells increases. However, halogen atoms form negative ions when they gain an electron to achieve a full outer shell. Since fluorine is the smallest halogen, its outermost shell is closest to the positive nucleus, resulting in the strongest ability to attract an electron and making it the most reactive. As you move down the group, the forces of attraction between the nucleus and the outermost shell decrease, making it harder for atoms to gain electrons and thus reducing their reactivity.

Question 21

Why is fluorine the most reactive halogen?

Answer 21

A: Fluorine is the most reactive halogen because it is the smallest halogen, which means its outermost shell is closest to the positive nucleus. This proximity results in the strongest ability to attract an electron, making fluorine highly reactive compared to other halogens.

Question 22

Q: How does the ability to attract electrons affect halogen reactivity?

Answer 22

A: The ability to attract electrons affects halogen reactivity, with stronger attractions leading to higher reactivity. Fluorine, being the smallest halogen, has the strongest ability to attract electrons due to its close proximity to the nucleus, resulting in the highest reactivity among halogens. As you move down the group, the ability to attract electrons decreases, leading to lower reactivity.

Question 23

Q: What is a halogen displacement reaction, and how does it occur?

Answer 23

A: A halogen displacement reaction occurs when a more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide. This happens because the reactivity of Group 7 elements decreases as you move down the group.

Question 24

Q: Describe the displacement reactions involving chlorine, bromine, and iodine.

Answer 24

A: 1. Chlorine with Bromine & Iodine: Chlorine, being the most reactive, displaces bromine or iodine from an aqueous solution of the metal halide. For example:

Chlorine + potassium bromide → potassium chloride + bromine

Bromine with Iodine: Bromine, being more reactive than iodine, displaces iodine from an aqueous solution of the metal iodide.
For example:
Bromine + potassium iodide → potassium bromide + iodine

Question 25

Q: Provide ionic equations for the displacement reactions of the halogens.

Answer 25

• Cl2 + 2Br - —> 2Cl - + Br2
• Cl2 + 2I - —> 2Cl - + I2
• Br2 + 2I - —> 2Br- + I2

Question 26

Q: Explain the reactions of halogens with metals and non-metals.

Answer 26

A: - Halogens react with metals to form ionic compounds known as metal halide salts. The number of halogen atoms in the compound depends on the valency of the metal. For example, sodium reacts with chlorine to form sodium chloride

Halogens also react with nonmetals to form simple molecular covalent structures. For instance, halogens react with hydrogen to form hydrogen halides. The reactivity decreases down the group, with fluorine being the most reactive.

Question 27

Q: What are the elements in Group 0 known as?

Answer 27

A: The elements in Group 0 of the periodic table are called the noble gases.

Question 28

Q: Describe the general physical properties of noble gases.

Answer 28

A: Noble gases are all non-metal, monatomic (exist as single atoms), colorless, non-flammable gases at room temperature. They have full outer shells of electrons, making their electronic configuration extremely stable. With the exception of helium, which has 2 electrons in its outer shell, noble gases have eight valence electrons

Question 29

Q: List the electronic configurations of the noble gases.

Answer 29

A: - Helium (He): 2

Neon (Ne): 2, 8
Argon (Ar): 2, 8, 8
Krypton (Kr): 2, 8, 18, 8
Xenon (Xe): 2, 8, 18, 18, 8

Question 30

Q: What are some uses of noble gases?

Answer 30

A: - Helium is used for filling balloons and weather balloons due to its low density and non-flammability.

Neon, argon, and xenon are used in advertising signs.
Argon is used to provide an inert atmosphere for welding and to fill light bulbs, as it glows brightly when a high potential difference is applied to the gas under low pressure.

Question 31

Q: Explain the trends in boiling point and density of noble gases.

Answer 31

A: - Noble gases have very low melting and boiling points, with an increase in boiling point as you move down the group due to an increase in relative atomic mass. Elements further down the group have higher boiling points but still below 0 °C.

Since noble gases are all gases at room temperature, individual atoms are widely spaced apart, giving them low densities. Density increases as you move down the group, with helium being the lightest and radon being the heaviest noble gas.

Question 32

Q: Where are the transition metals located on the periodic table?

Answer 32

A: The transition metals are located between Groups 2 and 3 in the center of the periodic table.

Question 33

Q: Describe the physical properties of transition metals.

Answer 33

A: Transition metals are very lustrous, hard, strong, and are good conductors of heat and electricity. They are highly dense metals and have very high melting points.

Question 34

Q: Why can transition metals have more than one oxidation state?

Answer 34

A: Transition metals can have more than one oxidation state because they can lose a different number of electrons depending on the chemical environment they are in

Question 35

Q: Explain the significance of compounds containing transition metals in different oxidation states.

Answer 35

A: Compounds containing transition metals in different oxidation states will have different properties and colores in aqueous solutions. This variation in properties allows for a wide range of applications and uses of transition metal compounds in various industries.

Question 36

Q: What are catalysts, and how do they function in a chemical reaction?

Answer 36

A: Catalysts are substances that speed up the rate of a chemical reaction without being consumed in the process. They do not take part in the reaction itself. Catalysts function by providing an alternative pathway for the reaction to proceed with lower activation energy, thereby increasing the reaction rate.

Question 37

Q: How do transition metals serve as catalysts?

Answer 37

A: Transition metals serve as catalysts due to their ability to interchange between a range of oxidation states. This enables them to form complexes with reagents, facilitating electron transfer between different chemical species within a reaction system. Transition metals can donate and accept electrons easily, allowing them to promote the formation of reaction intermediates and products

Question 38

Q: Provide examples of common transition metal catalysts and their applications.

Answer 38

A: 1. Iron (Fe): Used as a catalyst in the Haber Process for the production of ammonia from nitrogen and hydrogen.

Vanadium pentoxide (V2O5): Utilized in the Contact Process for the production of sulfuric acid from sulfur dioxide and oxygen.
Nickel (Ni): Employed in the hydrogenation of alkenes, where it catalyzes the addition of hydrogen to unsaturated hydrocarbons to form saturated hydrocarbons.

Question 39

Q: What are some key patterns of reactivity in the Periodic Table?

Answer 39

A: Elements in Group 1 and 2 are highly reactive. Metals in Group 1 and 2 become more reactive as you descend the group. Metals form ionic compounds with reactive non-metals. Non-metals in Group 7 become less reactive as you go down. Group 0 elements are unreactive

Question 40

Q: How do the reactivities of transition metals and Group 1 metals compare?

Answer 40

A: All Group 1 metals form ions with a +1 charge, while transition metals can form ions with variable charges. Transition metals are harder, stronger, and denser than Group 1 metals, with much higher melting points. However, transition metals are much less reactive than Group 1 metals. Group 1 metals readily react with water, oxygen, and halogens, while transition metals react slowly or not at all under similar conditions.

Question 41

Q: Provide an example of the difference in reactivity between a Group 1 metal and a transition metal.

Answer 41

A: A Group 1 metal tarnishes rapidly in the presence of oxygen, forming a metal oxide. For instance, the shiny appearance of the metal disappears within seconds when exposed to oxygen. On the other hand, transition metals, such as iron, react slowly with oxygen to form iron oxide (rust), and this reaction requires the presence of water. It may take several weeks for iron to visibly show signs of oxidation.

Question 42

Q: How do metal atoms form positive ions during a reaction?

Answer 42

A: Metal atoms form positive ions by losing electrons when they react with other substances. The tendency of a metal to lose electrons is a measure of its reactivity, with more reactive metals losing electrons more easily than less reactive ones.

Question 43

Q: Describe the reaction of metals with water.

Answer 43

A: Metals that react with water form a metal hydroxide and hydrogen gas. The general equation for this reaction is:

metal+water→metal hydroxide+hydrogen gas

Question 44

Q: Describe the reaction of metals with acids.

Answer 44

A: When metals react with dilute acids, such as hydrochloric acid (HCl), the hydrogen atom in the acid is replaced by the metal atom to produce a salt and hydrogen gas. The general equation for this reaction is

metal + acid —> metal salt + hydrogen gas

Question 45

Q: How are the reactions of metals with water and acids related?

Answer 45

A: In both reactions (with water and acids), metals become positive ions. The reactivity of metals is related to their tendency to become an ion, with more reactive metals losing electrons more easily.

Question 46

Q: What is the reactivity series, and how can it be determined experimentally?

Answer 46

A: The reactivity series is an order of metals based on their reactivity. It can be determined experimentally by observing the rate of reaction between metals and acids or metals and water. More reactive metals will produce hydrogen gas more vigorously, leading to a faster reaction rate

Question 47

How are carbon and hydrogen incorporated into the reactivity series?

Answer 47

A: Carbon and hydrogen are included in the reactivity series because they play different roles in understanding the reactions of metals and predicting how metals can be extracted from their ores. Carbon serves as a reducing agent for metal oxide ores, while hydrogen is involved in reactions with acids. Placing carbon in the reactivity series helps determine whether a metal oxide can be reduced by carbon. Metals below carbon can be extracted by heating the oxide with carbon, while metals higher than carbon require alternative extraction methods, such as electrolysis.

Question 48

Q: What are displacement reactions, and how do they relate to the reactivity series?

Answer 48

A: Displacement reactions occur when a more reactive metal displaces a less reactive metal from its compounds. The reactivity of metals decreases going down the reactivity series, meaning that a more reactive metal can displace a less reactive metal from its compounds.