Question

1. determine the formula for the following chemicals. /6 (12÷2)

formula | name | ionic, molecular, acid, base or hydrate
--- | --- | ---
| carbon tetrachloride (gaseous) |
| mercury (ii) nitrite |
| aqueous magnesium hydroxide |
| aqueous hydrogen fluoride |
| gold (iii) oxide |
| cobalt (ii) hexahydrate |

Explanation:

Step1: Carbon tetrachloride formula & type

Carbon (C) + 4 chloride (Cl): $\text{CCl}_4$, molecular (nonmetal-nonmetal)

Step2: Mercury (II) nitrite formula & type

$\text{Hg}^{2+}$ + $\text{NO}_2^-$: $\text{Hg(NO}_2\text{)}_2$, ionic (metal-nonmetal polyatomic)

Step3: Magnesium hydroxide formula & type

$\text{Mg}^{2+}$ + $\text{OH}^-$: $\text{Mg(OH)}_2$, base (aqueous hydroxide)

Step4: Aqueous HF formula & type

$\text{HF}_{(aq)}$, acid (aqueous hydrogen halide)

Step5: Gold (III) oxide formula & type

$\text{Au}^{3+}$ + $\text{O}^{2-}$: $\text{Au}_2\text{O}_3$, ionic (metal-nonmetal)

Step6: Cobalt (II) hexahydrate formula & type

$\text{Co}^{2+}$ + 6 $\text{H}_2\text{O}$: $\text{CoSO}_4\cdot6\text{H}_2\text{O}$ (note: standard cobalt(II) hexahydrate is sulfate; if general, $\text{CoX}_2\cdot6\text{H}_2\text{O}$, hydrate)

Answer:

Formula	Name	Ionic, molecular, acid, base or hydrate
$\text{Hg(NO}_2\text{)}_2$	mercury (II) nitrite	Ionic
$\text{Mg(OH)}_2$	aqueous magnesium hydroxide	Base
$\text{HF}_{(aq)}$	aqueous hydrogen fluoride	Acid
$\text{Au}_2\text{O}_3$	gold (III) oxide	Ionic
$\text{CoSO}_4\cdot6\text{H}_2\text{O}$	cobalt (II) hexahydrate	Hydrate