halogens group 7 Flashcards
What are the elements in Group 7 known as?
Halogens
The halogens include fluorine, chlorine, bromine, iodine, and astatine.
What is a characteristic of all halogens?
They each have seven electrons in their outermost shell.
What does it mean that halogens are diatomic?
They form molecules made of pairs of atoms sharing electrons.
What is the physical state and appearance of fluorine at room temperature?
Yellow gas
What is the physical state and appearance of chlorine at room temperature?
Pale yellow-green gas
What is the physical state and appearance of bromine at room temperature?
Red-brown liquid
What is the physical state and appearance of iodine at room temperature?
Grey solid
What trend is observed in the melting and boiling points of the halogens as you go down the group?
Melting and boiling points increase as you go down the group.
What causes the increase in melting and boiling points of halogens?
Increasing intermolecular forces as the atoms become larger.
What is the physical state of iodine at room temperature?
Crumbly solid
What types of compounds do halogens form when they react with metals?
Ionic compounds, specifically metal halide salts.
What charge does the halide ion carry?
-1 charge
Fill in the blank: The halogens decrease in reactivity moving ______ the group.
down
What happens during a halogen displacement reaction?
A more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide.
Which halogen is the most reactive?
Chlorine
Which halogen is the least reactive?
Iodine
What occurs when chlorine is added to potassium bromide solution?
A displacement reaction occurs, turning the solution orange as bromine is formed.
What occurs when bromine is added to potassium iodide solution?
Bromine displaces iodine, resulting in a brown color of iodine.
True or False: Chlorine can displace both bromine and iodine from their respective halide solutions.
True
In the reaction Cl2 + 2KBr → 2KCl + Br2, what is being displaced?
Bromine is being displaced.
What is the result of the reaction between bromine and potassium iodide?
Bromine displaces iodine, forming potassium bromide and iodine.
What are displacement reactions sometimes referred to as?
Single replacement reactions.
A student adds chlorine water to a solution of potassium bromide. Describe the observations and write the ionic equation for the reaction.
Observations (1 mark):
The solution turns orange/brown (due to formation of bromine).
Explanation (1 mark):
Chlorine is more reactive than bromine, so it displaces bromide ions.
Ionic Equation (1 mark):
Cl₂ + 2Br⁻ → 2Cl⁻ + Br₂
