group 7 Flashcards
(23 cards)
Which has a higher boiling point, fluorine or chlorine? Explain your answer.
Chlorine has a higher boiling point than fluorine because chlorine molecules are larger in size, resulting in more Van der Waals forces between the molecules. More energy is required to overcome these forces.
Write the electron configuration of a fluoride ion.
1s² 2s² 2p⁶
Give an equation for the oxidation of chloride ions to give chlorine.
2Cl⁻ → Cl₂ + 2e⁻
What happens to the number of principal energy levels down a group in the periodic table?
The number of principal energy levels increases.
How does the size of atoms change down a group?
The size of atoms increases.
What is the appearance of halogen molecules at room temperature?
- F₂: Paleyellow gas
- Cl₂: Pale green gas
- Br₂: Dark red/orange liquid
- I₂: Dark purple/black solid
True or False: Down the group, the ability of the halogen to act as an oxidizing agent increases.
False
Why does the ability of halogens to act as oxidizing agents decrease down the group?
- The size of the atom has increased
- More shielding
- The halogen will gain electrons less readily
What is observed when iodine is not a strong enough oxidizing agent to oxidize bromide ions?
No visible change
What type of reaction do fluoride and chloride undergo with H₂SO₄?
Acid-base reaction only
What types of reactions do bromide and iodide undergo with H₂SO₄?
- Acid-base reaction
- Redox reaction
What is produced when bromide ions react with sulfuric acid?
- Br₂
- SO₂
- H₂O
What is the observation when iodide reacts with sulfuric acid?
Black solid/purple gas (I₂)
What is the test for ammonium ions?
Add aqueous sodium hydroxide and heat; the gas produced will turn moist litmus paper blue.
What is the simplest ionic equation for the reaction of acidified silver nitrate with sodium chloride?
Ag⁺(aq) + Cl⁻(aq) → AgCl(s)
What indicates the presence of magnesium ions in a test?
Add sodium hydroxide (NaOH(aq)); a white ppt forms.
What is the result of adding sodium sulfate (Na₂SO₄(aq)) to barium nitrate (Ba(NO₃)₂(aq))?
A white precipitate forms.
What do you observe when sodium carbonate reacts with hydrochloric acid?
Effervescence
What is the resulting color of the gas produced when ammonium ions are tested?
Turns moist litmus paper blue
What is the general observation when halides react with sulfuric acid?
Choking gas (SO₂) and various colored precipitates depending on the halide.
What is the appearance of the solution when bromine is produced in a reaction?
Dark brown solution
What is the appearance of the solution when iodine is produced in a reaction?
Black ppt and purple gas (I₂)
Fill in the blank: Down the group, it becomes easier to act as a _______ agent and lose an electron.
reducing
