Reactions of the Halogens Flashcards

All 7 cards in this deck

What is the chemical test for chlorine gas?

Damp litmus paper is bleached (turns white).

What is seen when damp blue litmus paper is placed in chlorine gas?

It first turns red, then bleaches / turns white.

What type of compound is formed when a halogen reacts with a metal?

A metal halide (a salt).
e.g. iron + chlorine → iron chloride

What are the steps to write a balanced equation for a halogen reacting with a metal?
e.g. aluminium + bromine

1. Write the reactants, halogen as a diatomic molecule: $\mathrm{Al} + \mathrm{Br_2}$
2. Work out the metal halide formula from the charges: $\mathrm{AlBr_3}$
3. Balance: $2\mathrm{Al} + 3\mathrm{Br_2} \rightarrow 2\mathrm{AlBr_3}$

What do the halogens form when they react with hydrogen?

Hydrogen halides.
e.g. $\mathrm{H_2} + \mathrm{Cl_2} \rightarrow 2\mathrm{HCl}$

What is the name of the solution formed when hydrogen bromide dissolves in water?

Hydrobromic acid — hydrogen halides dissolve to form acidic solutions.

True or false? Fluorine reacts more vigorously with iron than iodine does.

True. Reactivity decreases down Group 7, so fluorine is the most vigorous.