inorganic & PT

• What do Group 2 metals lose when they react?

  They lose two electrons to form 2+ ions.
• Why do Group 2 metals form 2+ ions?

  To achieve a full outer shell.
• How does the atomic radius of Group 2 metals change down the group?

  The atomic radius increases down the group.
• What causes the increase in atomic radius in Group 2 metals?

  It is due to additional electron shells.
• How does reactivity change among Group 2 metals down the group?

  Reactivity increases down the group.
• What factors contribute to the increased reactivity of Group 2 metals down the group?

  Increased electron shielding and increased atomic radius make outer electrons easier to lose.

  
• What happens to the first ionisation energy of Group 2 metals down the group?

  It decreases down the group.
• Why does the first ionisation energy decrease down the group for Group 2 metals?

  Due to a greater atomic radius and increased shielding, making it easier for an electron to be removed.

  
• What are the reactions of Group 2 metals with water?

  • React to produce a metal hydroxide and hydrogen.
  • The metal hydroxide forms an alkaline solution.
  • Known as alkaline earth metals.

  
• What is produced when magnesium reacts with water?

  A metal hydroxide and hydrogen gas.
• How does magnesium react with liquid water compared to steam?

  It reacts very slowly with liquid water but much faster with steam.
• What is the appearance of magnesium burning in steam?

  It produces a bright white flame and forms magnesium oxide, a white powder.
• What do Group 2 metals form when they react with chlorine gas?

  • They form metal chlorides.
  • All metal chlorides are white precipitates.
  • Reactions become more vigorous down the group.

  
• What do Group 2 metals produce when they react with oxygen?

  • They form oxides.
  • The reaction is vigorous once initiated.
  • Strontium and barium can form metal peroxides with excess oxygen and heat.

  
• What occurs when Group 2 metals react with dilute acids?

  • They produce bubbles of hydrogen gas.
  • They form solutions of metal compounds.
• What do Group 2 hydroxides react with dilute acids to form?

  • They form a salt and water.
  • This is a type of neutralisation reaction.
  • The salt formed depends on the acid used.

  
• What salt is formed when hydrochloric acid reacts with Group 2 hydroxides?

  Chloride salts.
• What salt is formed when sulfuric acid reacts with Group 2 hydroxides?

  Sulfate salts.
• What salt is formed when nitric acid reacts with Group 2 hydroxides?

  Nitrate salts.
• How does the solubility of Group 2 hydroxides change down the group?

  • Solubility increases down the group.
  • Magnesium hydroxide is the least soluble.
  • Barium hydroxide is the most soluble.
• Why is magnesium hydroxide used in medicine?

  It is alkaline and can neutralise acids.
• How does the solubility of Group 2 sulfates change down the group?

  • Solubility decreases down the group.
  • Magnesium sulfate is the most soluble.
  • Barium sulfate is the least soluble.
• Why is barium sulfate useful in medicine?

  It is insoluble and cannot be absorbed into the blood, making it safe for use as a medical tracer.
• What does barium chloride test for?

  It tests for sulfate ions.
• What happens during the thermal decomposition of Group 2 carbonates?

  • They produce solid metal oxides and carbon dioxide.
  • The reaction requires heating in aerobic conditions.
  • More heat is required down the group due to increased thermal stability.

  
• What happens during the thermal decomposition of Group 2 nitrates?

  • They produce metal oxides, nitrogen dioxide, and oxygen.
  • The reaction requires heating in aerobic conditions.
  • More heat is required down the group due to increased thermal stability.

  
• How do Group 1 carbonates and nitrates behave during thermal decomposition?

  • They also undergo thermal decomposition upon heating in aerobic conditions.
  • Lithium behaves similarly to Group 2 elements.
  • Other Group 1 nitrates and carbonates do not decompose easily.

  
• What is the trend in thermal stability for Group 1 and Group 2 carbonates and nitrates?

  • More stable carbonates and nitrates form down the groups.
  • More heat energy is required for thermal decomposition.
  • Smaller ions have higher charge density and form less stable compounds.

  
• How can Group 1 and Group 2 elements be identified using flame tests?

  • Each metal has a unique flame colour.
  • The procedure involves cleaning a nichrome wire and observing the flame colour.
• What flame colour does lithium produce in a flame test?

  Red.
• What flame colour does sodium produce in a flame test?

  Orange/Yellow.
• What flame colour does potassium produce in a flame test?

  Lilac.
• What flame colour does magnesium produce in a flame test?

  No colour.
• What flame colour does calcium produce in a flame test?

  Brick red.
• What flame colour does strontium produce in a flame test?

  Crimson red.
• What flame colour does barium produce in a flame test?

  Pale green.
• What explains the formation of colours in flame tests?

  • Electron transitions occur when energy is absorbed.
  • Electrons are promoted to higher energy orbitals and then drop back down.
  • The emitted energy can produce visible light.

  
• Why might some atoms and ions not produce a colour in the flame test?

  Because the energy emitted may not have a wavelength in the visible light part of the electromagnetic spectrum.
• What are the Group 7 elements known as?

  Halogens.
• How do halogens achieve a full outer shell?

  By gaining an electron to form a 1- ion.