Inorganic chemistry

• State 3 characteristics of the Alkali Metals:

  Here:

  All have 1 electron in their outer shell

  1. low density
  2. stored under oil (to prevent reactions with oxygen or water)
  3. are soft (can be cut with a knife)
• How Do Group 1 elements react with non-metals? Why are these reactions similar for different Group 1 elements?

  They form ionic compounds which are soluble white solids which form colorless solutions - they all have 1 electron in the outer shell
• How do Group 1 elements react with water?

  They release hydrogen gas and form hydroxides which dissolve to form a alkaline solution;

  React vigorously with water fizzing and moving around on the surface of the water
• How does the reactivity change moving down Group 1? Why?

  Increases. Because as you go down the group, the distance between the nucleus and valence shell increase as the number of shells increase.

  The valence electrons are then further from the nucleus and easier to lose.
• Reactions of Alkali Metals in Oxygen:

  All Alkali metals react with oxygen to create an oxide
• Reactions of Alkali Metals in Water:

  more bubble = more vigorous reaction = more reactive metals
• Reactions of Alkali Metals in water{Lithuim}:

  fizzes steadily
• Reactions of Alkali Metals in water{Sodium}:

  Melts into a ball, then fizzes quickly
• Reactions of Alkali Metals in water{Potassium}:

  gives off sparkles, hydrogen burns with lilac flame
• State 5 Characteristics of Group 7:

  Here:

  • 7 electrons on their outer shell
  • Colored vapor
  • Diatomic molecules
  • Form ionic salts with metals
  • Form molecular compounds with non-metal
• Group 7 and their state of matter{Fluorine}:

  pale yellow gas
• Group 7 and their state of matter{Chlorine}:

  a pale green gas
• Group 7 and their state of matter{Bromine}:


  an orange brown liquid
• Group 7 and their state of matter{Iodine}:

  is a purple black solid
• Group 7 and their state of matter{Asatine}:

  solid at room temperature
• State 3 changes that occur in Group 7 as on moves down the group:

  here:

  • higher relative molecular mass
  • higher MP and BP
  • less reactive, electrons less easily gained
• Displacement Reaction Rule in Group 7:

  a more reactive halogen can displace a less reactive halogen in an aq solution of its salt
• Displacement Reactions on Group 7 Eg:

  Chlorine + Potassium Bromide -> Potassium Chloride + Bromine
• Displacement reactions in group 7 Reactivity trends:

  Chlorine: displaces bromine and iodine

  Bromine: displaces iodine but no chlorine

  Iodine: cannot displace chlorine or bromine
• Group 7 Reactivity Trend:

  reactivity decreases down the group
• Explain the trend in reactivity in Group 7 in terms of electronic configurations:

  The halogen react by gaining an electron in their outer shell, as you go down the group:

  • outer shell becomes further from the nucleus
  • electron shielding increases
  • attraction decreases between nucleus and outer electrons
  • electrons are gained easily
  • halogens become less reactive
• Proportions of gases in the atmosphere:

  78% Nitrogen(N)

  21% Oxygen(O)

  0.9% Argon

  0.037% Carbon Dioxide
• How have human activities led to an increase in greenhouse gases?

  carbon dioxide - > combustion of fossil fuels and deforestation

  Methane -> increases farming and decomposition in landfills
• Percentage of Oxygen in Air Experiment (Procedure:)

  Here:

  • pass 100cm^3 of air over heated copper using a Bunsen burner in a closed system
  • All oxygen reacts with copper
  • Volume of air decreases until it stops decreasing
  • Record the final volume in air
• Percentage of Oxygen in Air Experiment (Results):

  Approximately 79cm^3 of air remains, indicating 21cm^3 of the original 100cm^3 was oxygen
• Percentage of Oxygen in Air Experiment (Eg)

  Copper + Oxygen -> copper(ii) oxide

  Cu + O2 -> CuO

  -> black copper oxide forming
• Combustion of Elements in Oxygen(Definition):

  Combustion is an example of oxidation (substance gains oxygen)

  Both non-metals and metals can combust
• Combustion of Elements in Oxygen{Magnesium}:

  2Mg + O2 -> 2MgO
• Thermal Decomposition of Metal Carbonate -> General Reaction:

  Metal Carbonate(Metal) -> Metal Oxide+ Carbon dioxide
• Thermal decomposition of Metal Carbonates -> Eg:

  CuCo3 -> CuO +CO2
• Carbon Dioxide and Climate Change -> Greenhouse Gases:

  Carbon Dioxide -> contributes to greenhouse effect and climate change

  Water vapor -> H20

  Methane -> CH4
• Carbon Dioxide and Climate Change -> Greenhouse Effect:

  Here:

  • sun's electromagentic radiation passes through Earth's atmosphere
  • Earth absorbs and radiates some heat as IR
  • Greenhouse gases absorb some IR, warming the atmosphere
  • Leads to the greenhouse effect and global warming
• Carbon Dioxide and Climate Change -> Global Warming:

  Enhanced greenhouse effect causes an increase in average global temperature

  -> major cause of climate change
• Test for Hydrogen:

  Use a burning splint held at the open end of a test tube of the gas

  • creates a "squeaky pop" sound
• Test For Oxygen:

  Uses a glowing splint inserted into a tube of the gas

  • splint relights in Oxygen
• Test for Carbon Dioxide:

  Bubble the gas through lime water (calcium hydroxide) and it will turn milky(cloudy)
• Test for Ammonia:

  Make a damp red litmus paper blue

  • Forms a white smoke of ammonia chloride when hydrogen chloride gas, from concentrated hydrochloric acid, is held near it
• Test for Chlorine:

  When damp litmus paper is put into chlorine gas the litmus paper is bleached. It will first turn blue but will then be bleached and will turn white.
• How do you carry out a flame test:

  Take a sample of the metal on a wire and put it in a flame(Bunsen Burner(Blue flame)) the flame will turn a specific color, showing what metal it is
• Flame test colour for Lithium:

  Crimson red flame