Question

Many familiar substances have common, unsystematic names. For each of the following, give the correct systematic name: \((\mathbf{a})\)(b) soda ash, saltpeter, \((\mathbf{c})\)soda ash, \(\mathrm{Na}_{2} \mathrm{CO}_{3}$$(\mathbf{d})\)muriatic acid, HCl;\((\mathbf{e})\)Epsom salts, \(\mathrm{Mg} \mathrm{SO}_{4}$$(\mathbf{f})\)milk of magnesia \(\mathrm{Mg}(\mathrm{OH})_{2}\)

Short answer

The systematic names for the given substances are as follows: (a) sodium carbonate, (b) potassium nitrate, (c) sodium carbonate, (d) hydrogen chloride or hydrochloric acid, (e) magnesium sulfate, and (f) magnesium hydroxide.

Step-by-step solution

(a) Soda ash

The chemical formula for soda ash is \(Na_2CO_3\). The systematic name for this compound is sodium carbonate.

(b) Saltpeter

Saltpeter refers to \(KNO_3\). The systematic name for this compound is potassium nitrate.

(c) Soda ash (repeated)

As previously mentioned, the chemical formula for soda ash is \(Na_2CO_3\), and the systematic name is sodium carbonate.

(d) Muriatic acid

The chemical formula for muriatic acid is \(HCl\). The systematic name for this compound is hydrogen chloride or hydrochloric acid when in a water solution.

(e) Epsom salts

The chemical formula for Epsom salts is \(MgSO_4\). The systematic name for this compound is magnesium sulfate.

(f) Milk of magnesia

The chemical formula for milk of magnesia is \(Mg(OH)_2\). The systematic name for this compound is magnesium hydroxide.

Key concepts

Chemical Nomenclature

Understanding the names of chemical compounds is crucial for anyone studying chemistry. Chemical nomenclature is the systematic method for naming chemical substances. Each name provides valuable information about the composition and structure of a compound.

For instance, in the exercise given, 'soda ash' is more commonly referred to as sodium carbonate, which tells us that the compound consists of sodium (Na), carbon (C), and oxygen (O) in specific proportions, as dictated by the chemical formula \(Na_2CO_3\). Similarly, 'Epsom salts' are known scientifically as magnesium sulfate, denoting a compound composed of magnesium (Mg), sulfur (S), and oxygen (O), with the formula \(MgSO_4\).

The names of inorganic compounds, in particular, often include prefixes and suffixes that indicate the number of atoms in the compound, the oxidation states of the elements, and whether the compound is an acid, a base, or a salt. For example, in hydrogen chloride \(HCl\), 'hydrogen' indicates the presence of hydrogen, and 'chloride' signifies the chlorine component, also suggesting that chlorine is in a negative oxidation state.

Inorganic Compounds

Inorganic compounds are a class of compounds that typically lack carbon-hydrogen bonds, differentiating them from organic compounds. These include metals, salts, minerals, and compounds such as acids and bases.

The systematic naming of inorganic compounds follows strict rules set out by the International Union of Pure and Applied Chemistry (IUPAC). The exercise lists 'saltpeter', which is the common name for the inorganic compound \(KNO_3\), known systematically as potassium nitrate. Here, 'potassium' identifies the metal cation (\(K^+\)), while 'nitrate' describes the anion made of nitrogen and oxygen (\(NO_3^-\)).

Inorganic nomenclature helps ensure that chemical names convey precise information about their chemical structure. This allows scientists and students to understand compounds’ properties, reactions, and uses. By learning the systematic names, one can decipher the types of atoms in a compound and their ratios, such as the \(Mg(OH)_2\) composition of 'milk of magnesia' which is systematically named magnesium hydroxide.

Chemical Formulas

Chemical formulas are essential for understanding the composition of compounds. They use element symbols and numerical subscripts to depict the types and numbers of atoms present in a single molecule of a compound. This concise representation is fundamental in visualizing the compound's structure and predicting its properties and behavior during chemical reactions.

For example, the chemical formula for 'muriatic acid' is \(HCl\), illustrating that this compound is composed of one hydrogen atom and one chlorine atom. When this compound is dissolved in water, it is referred to as hydrochloric acid, which highlights the context-dependent aspect of nomenclature in chemistry.

Being able to interpret and write chemical formulas is a key skill in chemistry. It requires an understanding of valency, which is the combining power of an element, and the ability to balance charges to determine the correct stoichiometric ratios, as evident in the provided exercise with sodium carbonate (\(Na_2CO_3\)), where the subscript '2' indicates that there are two sodium atoms for every one carbon and three oxygen atoms.