Formulae: แบบฝึกหัด

Which statement correctly defines the molecular formula of a compound?

A compound contains only the ions \(Fe^{3+}\) and \(O^{2-}\). What is the correct chemical formula for this ionic compound?

When aqueous silver nitrate, \(AgNO_{3}(aq)\), is added to aqueous sodium chloride, \(NaCl(aq)\), a white precipitate of silver chloride forms.

Which of the following is the correct ionic equation for this reaction, including state symbols?

What is the chemical formula for the ionic compound ammonium sulfate?

An ionic compound is formed between aluminium ions, \(Al^{3+}\), and sulfide ions, \(S^{2-}\).

What is the correct formula for this compound?

State the definition of the molecular formula of a compound.

Construct the balanced ionic equation, including state symbols, for the reaction between aqueous silver nitrate and aqueous potassium iodide.

A compound contains \(52.2\%\) carbon, \(13.0\%\) hydrogen, and \(34.8\%\) oxygen by mass. Determine its empirical formula.
\((A_r: C=12.0, H=1.0, O=16.0)\)

Construct the chemical formulae for the following ionic compounds by considering the charges on the ions:
(a) Sodium phosphate
(b) Calcium nitrate
(c) Iron(III) hydroxide

An oxide of iron is formed by reacting \(2.24\text{ g}\) of iron with excess oxygen. The resulting compound has a mass of \(3.20\text{ g}\).
(a) Determine the mass of oxygen that reacted with the iron.
(b) Calculate the empirical formula of this iron oxide.
(Relative atomic masses: Fe = 56, O = 16)