Some Reactions of the Halide Ions (CIE A Level Chemistry)

What is the complete list of all the products from the reaction of potassium bromide with concentrated sulfuric acid?

Astatine is the element below iodine in Group 17 of the Periodic Table.

Which statement is most likely to be true for astatine?

An unlabeled powder is known to be either a single sodium halide or a mixture of two different sodium halides. 

To determine what the powder consists of a sample of the powder was first dissolved in water. Then acidified aqueous silver nitrate was added to the new solution, and a pale yellow precipitate was formed. When concentrated aqueous ammonia was added, the precipitate partly dissolved, leaving a darker yellow precipitate. 

What might the powder have consisted of?

Solid potassium halides react with concentrated sulfuric acid, according to the following equations.

Reaction 1:     2KCl + H₂SO₄ → K₂SO₄ + 2HCl

Reaction 2:     2KBr  +  2H₂SO₄  →  K₂SO₄  +  SO₂  +  Br₂  +  2H₂O

Reaction 3:     8KI +  5H₂SO₄  →  4K₂SO₄  +  H₂S  +  4I₂  + 4H₂O

What is the largest change in the oxidation number of sulfur in each of these reactions?

A student observed the reactions when sodium bromide and sodium fluoride were each reacted separately with concentrated sulfuric acid and concentrated phosphoric acid. 

The observations are recorded in the table below.

Which deduction can be made from these observations?

The following two experiments are carried out with anhydrous potassium chloride and observations X and Y are made at the end of each experiment. 

The potassium chloride is dissolved in aqueous silver nitrate, and this is then added to aqueous ammonia- observation X. 

Concentrated sulfuric acid is added to the potassium chloride, and the fumes produced are bubbled into aqueous potassium iodide solution - observation Y. 

What are the observations X and Y?

Element 85, astatine, is a halogen. If concentrated sulfuric acid is added to sodium astatide the resultant products are a mix of astatine, hydrogen astatide, hydrogen sulfide and sodium sulfate.

Which product is formed by the oxidation of one of the constituents of sodium astatide?

Q is a salt of one of the Group 17 elements chlorine, bromine, iodine, or astatine.

The reaction scheme shows a series of reactions using a solution of Q as the starting reagent.

What could Q be?

Two students, R and S, were asked to draw bar charts to represent how some properties of the halogens and their compounds differ in magnitude. Their diagrams are shown.

Which of the student’s diagrams are correct?

X, Y and Z represent different halogens. The table shows the results of nine experiments in which aqueous solutions of X₂, Y₂ and Z₂ were separately added to separate aqueous solutions containing X^-, Y^- and Z^- ions.

Which row in the following table contains the ions X-, Y- and Z-  in order of their decreasing strength as reducing agents?