Group 1,7, reactivity, chemical tests

• What is the name given to group 7?

  halogens
• what does chlorine look like?

  green gas
• What does bromine look like?

  red-brown liquid that gives off an orange vapour
• What does iodine look like?

  dark grey crystalline solid that gives off purple vapour
• When does iodine give off its purple vapour?

  when heated
• When does bromine give of its orange vapour?

  at room temperature
• Suggest what colour asataine is and why?

  black because as the atomic number increases elements have a darker colour
• What is chlorine's physical state at room temp?

  gas
• What is bromine's physical state at room temp?

  liquid
• What is iodine's physical state at room temp?

  solid
• What happens to the reactivity as you go down group 7?

  reactivity decreases
• Why does reactivity decrease as you move down group 7?

  it gets harder to attract the extra electron to fill the outer shell when it's further away from the nucleus due to weaker force of attraction
• What happens when you add chlorine water to potassium chloride?

  no reaction
• What happens when you add bromine water to potassium chloride?

  no reaction
• What happens when you add iodine water to potassium chloride?

  no reaction
• What happens in a displacement reaction?

  move reactive halogens displace less reactive ones
• What happens when you add chlorine water to potassium bromide?

  orange solution formed
• What happens when you add bromine water to potassium bromide?

  no reaction
• What happens when you add iodine water to potassium bromide?

  no reaction
• What happens when you add chlorine water to potassium iodide?

  brown solution formed
• What happens when you add bromine water to potassium iodide?

  brown solution
• What happens when you add iodine water to potassium iodide?

  no reaction
• In a displacement reaction what is a loss of electrons called?

  oxidation
• In a displacement reaction what is a gain of electrons called?

  reduction
• What does OILRIG stand for in a displacement reaction?

  oxidation is loss, reduction is gain
• An oxidising agent gains electrons so gets reduced
• A reducing agend gives electrons and gets oxidised
• What is a redox reaction?

  when both oxidation and reduction take place
• What are group 1 metals known as?

  alkali metals
• What happens to the reactivity of froup 1 as you go down the group?

  increases
• Why does the reactivity increase as you move down group 1?

  as you go down, the outer electron is easier to lose as attraction between electron and nucleus is less
• What are the observations of lithium plus water?

  skates across surface of water, effervescence, universal indicator goes blue
• What are the products when you add an alkali metal to water?

  metal hydroxide and hyrdogen
• What are the observations of sodium plus water?

  skates across surface of water, melts into ball, universal indicator goes blue, fizzes vigorously
• What are the observations when you add potassium to water?

  skates across water, lilac flames and sparks, universal indicator goes blue, fizzes vigorously
• Why does chlorine, a halogen have a low melting point?

  weak intermolecular forces
• Does chlorine conduct electricity, why, why not?

  no because there's no delovalised electrons
• What number do you use in a displacement reaction when finding out oxidised or reduction for an element on its own?

  0
• What number do you use in a displacement reaction when finding out oxidised or reduction for an compound on its own?

  -1 charge
• if something loses electrons so becomes oxidised it is more positive so -1 to 0