Chemical properties of the group 7 elements
The smallest part of an element that can exist. of The vertical column of non-metal elements next to group 0 in the periodic table, also called the halogens.A substance made of one type of atom only. all have seven Subatomic particle, with a negative charge and a negligible mass relative to protons and neutrons. in their outer shell. This means that the An element placed in group 7 of the periodic table, which starts with fluorine and ends with astatine. The name 'halogen' means 'salt-producing' because halogens produce a range of salts when they react with metals. all have similar A description of how a substance reacts with other substances. For example, flammability, pH, reaction with acid, etc..
Reactions with group 1 metals
The halogens react with Shiny element that is a good conductor of electricity and heat, and which forms basic oxides. to produce The substance formed when the hydrogen ion in an acid is replaced by a metal ion. (the word 'halogen' means 'salt former'). For example, chlorine reacts with sodium:
sodium + chlorine → sodium chloride
2Na(s) + Cl2(g) → 2NaCl(s)
Sodium and chlorine react vigorously when heated, giving an orange flame and clouds of white sodium chloride.
The halogens become less The tendency of a substance to undergo a chemical reaction. going down group 7.
Question
Write the A chemical equation written using the symbols and formulae of the reactants and products, so that the number of units of each element present is the same on both sides of the arrow. for the reaction of lithium with bromine to produce lithium bromide, LiBr. Include state symbols.
2Li(s) + Br2(g) → 2LiBr(s)
Chemical test for chlorine
Damp litmus paper is bleached white when it is placed in chlorine. If damp-blue litmus paper is used, the paper turns red then white.
Halogen displacement reactions
A more reactive An element placed in group 7 of the periodic table, which starts with fluorine and ends with astatine. The name 'halogen' means 'salt-producing' because halogens produce a range of salts when they react with metals. can Take the place of another substance in a chemical reaction. For example, a metal can displace a less reactive metal from its oxide, removing oxide ions from the less reactive metal and becoming an oxide itself. a less reactive halogen from Mixture formed by a solute and a solvent. of its The substance formed when the hydrogen ion in an acid is replaced by a metal ion.. For example, chlorine is more reactive than iodine. A solution of chlorine can displace iodine from potassium iodide solution:
chlorine + potassium iodide → potassium chloride + iodine
Cl2(aq) + 2KI(aq) → 2KCl(aq) + I2(aq)
The reaction mixture turns darker and iodine solution forms.
Determining a reactivity series
A A list of elements in order of their reactivity, usually from most reactive to least reactive. can be worked out by carrying out several A reaction that occurs when a more reactive element replaces a less reactive element in a compound.. Different combinations of halogen solution and salt solution should be tested so that a reactivity series for Group 7 can be worked out:
- the most reactive halogen displaces all of the other halogens from solutions of their salts, and is itself displaced by none of the others
- the least reactive halogen displaces none of the others, and is itself displaced by all of the others
It doesn't matter whether sodium salts or potassium salts are used - it works the same for both types of salt.
The periodic table, containing all the known elements, arranged in groups and periods
