Halogens Flashcards
What are the halogens?
The halogens are a group of elements in Group 17 of the periodic table, including fluorine, chlorine, bromine, iodine, and astatine.
Which halogen is the most reactive?
Fluorine is the most reactive halogen.
True or False: Chlorine is a gas at room temperature.
True.
What is the physical state of bromine at room temperature?
Bromine is a liquid at room temperature.
Fill in the blank: The halogens are known for forming ______ with metals.
salts.
What is the trend in reactivity of the halogens as you move down the group?
Reactivity decreases as you move down the group.
Which halogen is used in water treatment to kill bacteria?
Chlorine.
What is the color of chlorine gas?
Chlorine gas is green
What is the common oxidation state of halogens in their compounds?
-1.
Multiple Choice: Which of the following is a property of halogens? A) Good conductors of electricity B) Brittle solids C) Diatomic molecules D) All of the above
C) Diatomic molecules.
What type of bond do halogens typically form with hydrogen?
Covalent bonds.
True or False: Astatine is a stable isotope.
False.
What is the trend in boiling points of the halogens as you move down the group?
Boiling points increase as you move down the group.
Which halogen is used in the production of fluorinated compounds?
Fluorine.
Fill in the blank: The halogens can form ______ ions.
halide.
What is the most common use of iodine?
Iodine is commonly used as an antiseptic.
Which halogen has the highest atomic number?
Astatine.
What happens to the size of halogen atoms as you move down the group?
The size of halogen atoms increases as you move down the group.
What is the electronegativity trend among the halogens?
Electronegativity decreases as you move down the group.
Which halogen is a solid at room temperature?
Iodine.
What is the primary application of chlorine in industry?
Chlorine is primarily used in the production of plastics, especially PVC.
True or False: Halogens can act as oxidizing agents.
True.
What is the bond type in the diatomic molecule of a halogen?
Covalent bond.
Which halogen is used in the synthesis of pharmaceuticals?
Fluorine.
What is the main characteristic of halogens in terms of their reactivity?
Halogens readily gain electrons to achieve a full outer shell.
Fill in the blank: The halogen with the lowest melting point is ______.
Fluorine.
What is a disproportionation reaction
What’re the same thing is both oxidised and reduced .
Chlorine is a toxic gas why is it used for water treatment
Benefit outways the risks
As chlorine kills bacteria. So we don’t get things like cholera
What is a reducing agent
Something that is oxidised
It donates electrons (loss of electrons)
Larger ions are better reducing agents
Reducing power increases down the group the
What happens to the boiling point going down group 7
increases as we go down the group because the van der waals forces increase due to the increasing relative mass and size of the atoms.
What happens to the electronegativity down group 7
Decreases as we go down the group
Electronegativity it the ability for an atom to attract electrons towards itself in a covalent bond.
At atoms get larger and the distance between the positive nucleus and the bonding electrons increases. There is also more shielding .
Name the colours and states of the halogens a room temp
Fluorine: pale yellow gas
Chlorine: pale green gas
Bromine: brown-orange liquid
Iodine: grey solid
What is the core rule with halogen displacement reactions
A MORE REACTIVE HALOGENS WILL DISPLACE A LESS REACTIVE HALIDE ION
What happens to the reactivity going down group 7
The reactivity decreases
For a reaction to occur an electron is gained. Atoms with a smaller radius attract electrons better than larger ions.
The atomic radius increases down group 7
State and explain what happens to electronegativity of the halogens going down the group
Electronegativity decreases down the group :
Moving down the group the number of electron shells increases in each atom, meaning that the outermost electrons have more inner shells between them and the nucleus. These extra inner shells ‘shield’ the positive charge from the nucleus that reaches the outermost electrons. This is known as inner electron shielding.
As the positive charge felt on the surface of the atom is reduced, the halogen is less able to attract electrons in a covalent bond towards itself
Define the terms volatile and sublimes
Volatile- evaporates easily
Sublimes- changes state from a solid to gas with no liquid state
How do we test the reducing power of the halides
React them with concentrated sulfuric acid
The reaction occur in 2 stages
1. Acid-base reaction- all halides react with sulfuric acid in a acid base reaction to produce the acid halide these are NOT redox reactions
2. Reduction of sulfuric (only Br- and I-)
What happens to the reducing power going down group 7
The reducing power increases (halides are more easily oxidised)
. Atomic radius increases down the group and the larger ions have more shielding
. therefore there is a weaker attraction between the nucleus and outermost electron
.the ion is then more likely to donate electrons and be stronger reducing agents
. Strongest oxidising agents = At- and I-
What is fluorine’s appearance at room temperature
Ale yellow gas
What is bromines appearance at room temperature
Dark red volatile liquid / brown Vapor
What is bromines appearance in solution
Orange/yellow solution
What is iodines appearance at room temperature
Shiny black solid
Sublimes to give a purple Vapor
What is iodines appearance in solution
Brown solution
How is bromine extracted from sea water
REDOX reaction
