Alkaline earth metals

Question 1

Describe the trend in atomic radius for alkaline earth metals as you move down the group.

Answer 1

The atomic radius increases down the group due to more electron shells and increased shielding from inner shells.

Question 2

Explain the relationship between ionic radius and atomic radius in alkaline earth metals.

Answer 2

The ionic radius is smaller than the atomic radius because when forming a 2+ ion, two electrons are lost, resulting in one less shell.

Question 3

How does the first ionization energy change down the alkaline earth metals group?

Answer 3

The first ionization energy decreases down the group due to more electron shells, increased shielding, and a greater number of protons that are outweighed by the effects of shells and shielding.

Question 4

Define reactivity in the context of alkaline earth metals.

Answer 4

Reactivity refers to the tendency of alkaline earth metals to lose two electrons and form a 2+ ion when they react, which increases down the group as ionization energies decrease.

Question 5

What happens to the melting point of alkaline earth metals as you move down the group?

Answer 5

The melting point decreases down the group due to an increase in ionic radius, which weakens the attraction between the 2+ charge from the nucleus and the delocalized electrons.

Question 6

Explain why magnesium has an unusually low melting point compared to other alkaline earth metals.

Answer 6

Magnesium’s unusually low melting point is attributed to the different arrangement of ions in its crystal structure.

Question 7

Do alkaline earth metals lose electrons easily as you move down the group?

Answer 7

Yes, alkaline earth metals lose electrons more easily as you go down the group due to decreasing ionization energies.

Question 8

How does the number of protons affect the first ionization energy in alkaline earth metals?

Answer 8

While the number of protons increases down the group, the effect is outweighed by the increased number of electron shells and shielding, leading to a decrease in first ionization energy.

Question 9

Describe the reactivity trend of Group 2 elements.

Answer 9

Group 2 metals become more reactive as you go down the group due to a decrease in ionisation energies.

Question 10

Explain the reaction of Group 2 metals with water.

Answer 10

Group 2 metals react with water to produce a metal hydroxide and hydrogen gas.

Question 11

How do Group 2 metals react with water?

Answer 11

The reaction can be represented as: Metal + Water → Metal hydroxide + Hydrogen.

Question 12

Define the reaction of magnesium with steam.

Answer 12

Magnesium reacts with steam to produce magnesium oxide and hydrogen gas.

Question 13

What is the general equation for the reaction of magnesium with steam?

Answer 13

Mg (s) + H2O (g) → MgO (aq) + H2 (g).

Question 14

Explain the solubility trend of hydroxides in Group 2 elements.

Answer 14

The solubility of hydroxides tends to increase as you go down the group.

Question 15

Describe the solubility of magnesium hydroxide.

Answer 15

Magnesium hydroxide (Mg(OH)2) is considered to be sparingly soluble.

Question 16

What is the solubility of barium sulfate in Group 2 elements?

Answer 16

Barium sulfate (BaSO4) is insoluble.

Question 17

How do negatively charged ions affect the solubility of compounds in Group 2 elements?

Answer 17

Negatively charged ions tend to influence solubility trends as you go down the group.

Question 18

Explain the ionisation process of Group 2 metals during reactions.

Answer 18

Group 2 metals lose 2 electrons (2e-) when they react, forming M2+ ions.

Question 19

Describe the relationship between the solubility of Group 2 hydroxides and the pH of the solution.

Answer 19

As solubility increases, more OH- ions are released, resulting in a more alkaline solution and an increase in pH down the Group.

Question 20

Explain how to test the solubility of Group 2 hydroxides.

Answer 20

Add hydroxide ions, OH-, to a solution of the Group 2 ion, M2+. The reaction forms M(OH)2(s), where the solubility varies among the hydroxides.

Question 21

Define the solubility characteristics of Group 2 sulphates.

Answer 21

Most Group 2 sulphates are soluble, ranging from sparingly soluble to soluble, except for barium sulphate, which is insoluble.

Question 22

How is the presence of sulphate ions tested using barium chloride?

Answer 22

Add HCl first to remove any interfering sulphites or carbonates, then add BaCl2 solution. A white precipitate of BaSO4 will form if sulphates are present.

Question 23

Explain the significance of barium sulphate in testing for sulphate ions.

Answer 23

Barium sulphate is used as a chemical test for the presence of sulphate ions because it is insoluble and forms a white precipitate.

Question 24

Describe the outcome when testing the solubility of magnesium sulphate.

Answer 24

Magnesium sulphate (MgSO4) is soluble, so no precipitate will form when tested.

Question 25

What happens when barium hydroxide is tested for solubility compared to magnesium hydroxide?

Answer 25

Barium hydroxide is more soluble and forms a thin white precipitate, while magnesium hydroxide is sparingly soluble and forms a thick white precipitate.

Question 26

How do hydroxides affect the alkalinity of a solution?

Answer 26

The release of OH- ions from hydroxides increases the alkalinity of the solution.

Question 27

Explain the process of forming a precipitate when testing for sulphate ions.

Answer 27

When barium ions (Ba2+) react with sulphate ions (SO4 2-), they form barium sulphate (BaSO4), which is a white precipitate.

Question 28

Describe the flame color produced by Calcium ions (Ca 2+) during a flame test.

Answer 28

Calcium ions produce a brick red flame color during a flame test.

Question 29

Explain the significance of Barium sulphate (BaSO4) in medical imaging.

Answer 29

Barium sulphate is used in barium meals for X-ray imaging as it does not allow X-rays to pass through, helping to visualize the oesophagus, stomach, or intestines.

Question 30

Define the process of extracting Titanium from TiO2.

Answer 30

Titanium is extracted from TiO2 by converting it to TiCl4 through heating with carbon and chlorine, followed by reduction with magnesium.

Question 31

How does magnesium act as a reducing agent in the extraction of Titanium?

Answer 31

Magnesium acts as a reducing agent by being oxidized from 0 to +2 while reducing TiCl4 from +4 to 0 during the extraction of Titanium.

Question 32

Explain the process of wet scrubbing for removing SO2 from flue gases.

Answer 32

Wet scrubbing involves reacting SO2 with an alkali like CaO or CaCO3 slurry to form calcium sulfite, effectively removing SO2 from flue gases.

Question 33

Describe the reaction that occurs when CaO is used to neutralize SO2.

Answer 33

The reaction is: CaO (s) + 2 H2O (l) + SO2 (g) → CaSO3 (aq) + 2 H2O (l).

Question 34

What is the role of Group 2 hydroxides in agriculture and medicine?

Answer 34

Group 2 hydroxides are alkaline and can neutralize acids; for example, Ca(OH)2 is used to neutralize acidic soils, and Mg(OH)2 is used to neutralize excess stomach acids.

Question 35

Identify the flame color associated with Strontium ions (Sr 2+) during a flame test.

Answer 35

Strontium ions produce a red flame color during a flame test.

Question 36

What flame color is produced by Barium ions (Ba 2+) in a flame test?

Answer 36

Barium ions produce a pale green flame color during a flame test.

Question 37

Explain why other Barium compounds cannot be used for X-ray imaging.

Answer 37

Other Barium compounds are soluble and can be poisonous, making them unsuitable for use in X-ray imaging.

Question 38

Describe the chemical reaction involved in the neutralization of acidic soils using Ca(OH)2.

Answer 38

Ca(OH)2 reacts with acids in the soil to neutralize them, helping to improve soil pH.

Question 39

What happens to magnesium during the reduction of TiCl4?

Answer 39

Magnesium is oxidized from 0 to +2 during the reduction of TiCl4.

Question 40

How is CaCO3 used in the removal of SO2 from flue gases?

Answer 40

CaCO3 reacts with SO2 in a slurry to form calcium sulfite and carbon dioxide, aiding in the removal of SO2.