Question

How can you use some or all of these substances to obtain ammonia gas, the brown ring compound, carbon dioxide?

iron
iron (II) sulphate
concentrated sulphuric acid
ammonium chloride
sodium nitrate
calcium hydroxide
lithium carbonate

Answer 1

Well you could liberate carbon dioxide from lithium carbonate by the action of conc. sulfuric acid......

Explanation:

And we would represent this by the chemical equation.....

`Li_2CO_3(aq) + H_2SO_4(aq) rarr Li_2SO_4(aq) + H_2O(l) + CO_2(g)uarr`

Is it balanced?

Answer 2

Here's what I get.

Explanation:

Ammonia gas

Heat a finely divided mixture of ammonium chloride and calcium hydroxide.

`"2NH"_4"Cl(s)" + "Ca(OH)"_2"(s)" stackrelcolor(blue)(Δcolor(white)(mm))(→) "CaCl"_2"(s)" + "2NH"_3"(g)" +2"H"_2"O(g)"`

The brown ring

Slowly add (without mixing) concentrated sulfuric acid to a test tube containing an aqueous solution of sodium nitrate and iron(II) sulfate.

The denser sulfuric acid will sink to the bottom and a brown ring will form at the junction of the two layers.

The reaction takes place in two stages.

First, the nitrate ion oxidizes the `"Fe"^"2+"` to `"Fe"^"3+"` and is in turn reduced to `"NO"`.

`"NO"_3^"-" + "3Fe"^"2+" + 4"H"^"+" → "NO" + "3Fe"^"3+" + 2"H"_2"O"`

Then, the `"NO"` attaches to the excess hydrated `"Fe"^"2+"` ions to form a brown nitrosyl complex.

`underbrace("Fe"("H"_2"O")_6^"2+")_color(red)("hexaaquairon(II) ion") + "NO" → underbrace("Fe"("H"_2"O")_5("NO")^"2+")_color(red)("pentaaquanitrosyliron(II) ion") + "H"_2"O"`

Carbon dioxide

Add the sulfuric acid to the sodium carbonate.

`"Li"_2"CO"_3"(s)" + "H"_2"SO"_4"(l)" → "Li"_2"SO"_4"(s)" + "CO"_2"(g)" + "H"_2"O(l)"`