Problem 82 - Chemistry The Central Science

Question

What is the anhydride for each of the following acids: (a) \(\mathrm{H}_{2} \mathrm{SO}_{4},(\mathbf{b}) \mathrm{HClO}_{3},(\mathbf{c}) \mathrm{HNO}_{2},(\mathbf{d}) \mathrm{H}_{2} \mathrm{CO}_{3},(\mathbf{e}) \mathrm{H}_{3} \mathrm{PO}_{4} ?\)

Step-by-Step Solution

Answer

The anhydrides for the given acids are: (a) H2SO4: \( \mathrm{SO}_{3} \), (b) HClO3: \( \mathrm{Cl}_{2} \mathrm{O}_{3} \), (c) HNO2: \( \mathrm{N}_{2} \mathrm{O}_{3} \), (d) H2CO3: \( \mathrm{CO}_{2} \), and (e) H3PO4: \( \mathrm{P}_{2} \mathrm{O}_{5} \).

Step 1: Identify the water molecule in each acid

For each of the given acids, we need to find the water molecule (H2O) that can be removed to form the anhydride. A good way to approach this is to focus on the hydrogens (H) that can combine with oxygen (O) to form H2O.

Step 2: Remove water molecule and rewrite the anhydride formula

For each given acid, remove the H2O molecule and rewrite the chemical formula for the anhydride. Here's the solution for each of the acids: (a) H2SO4 Anhydride: \( \mathrm{SO}_{3} \) (removing H2O from the formula) (b) HClO3 Anhydride: \( \mathrm{Cl}_{2} \mathrm{O}_{3} \) (removing H2O from the formula) (c) HNO2 Anhydride: \( \mathrm{N}_{2} \mathrm{O}_{3} \) (removing H2O from the formula) (d) H2CO3 Anhydride: \( \mathrm{CO}_{2} \) (removing H2O from the formula) (e) H3PO4 Anhydride: \( \mathrm{P}_{2} \mathrm{O}_{5} \) (removing 1/2 H2O per phosphorus atom)

Step 3: State the anhydrides of the given acids

The anhydrides for each of the given acids are: (a) H2SO4: \( \mathrm{SO}_{3} \) (b) HClO3: \( \mathrm{Cl}_{2} \mathrm{O}_{3} \) (c) HNO2: \( \mathrm{N}_{2} \mathrm{O}_{3} \) (d) H2CO3: \( \mathrm{CO}_{2} \) (e) H3PO4: \( \mathrm{P}_{2} \mathrm{O}_{5} \)

Key Concepts

Chemical Formulas

Chemical formulas are a concise way to represent chemical compounds. They show the number and type of atoms present in the smallest unit of a substance. Each element is represented by its chemical symbol, with subscript numbers indicating the amount of each element in the compound.

• The formula \(\mathrm{H}_{2} \mathrm{SO}_{4}\) tells us there are 2 hydrogen atoms, 1 sulfur atom, and 4 oxygen atoms.
• In \(\mathrm{HClO}_{3}\), it denotes 1 hydrogen, 1 chlorine, and 3 oxygens.
• These formulas help identify how atoms bond to form different substances.

Chemical formulas are crucial in chemistry for understanding the composition of compounds. They serve as a basic language for chemists to communicate information about chemical substances accurately.

Water Molecule Removal

The process of forming an anhydride involves the removal of water molecules from an acid. This operation is fundamental in organic and inorganic chemistry, as it transforms acids into their corresponding anhydrides.

To remove a water molecule (\(H_2O\)), one has to look for two hydrogen atoms (\(H\)) and one oxygen atom (\(O\)) in the acid's chemical formula.

• For \(\mathrm{H}_{2}\mathrm{SO}_{4}\), when you remove \(H_2O\), you're left with \(\mathrm{SO}_{3}\), the anhydride.
• In the case of \(\mathrm{HClO}_{3}\), dropping the water molecule gives \(\mathrm{Cl}_{2}\mathrm{O}_{3}\).
• This method is systematic across different acids, ensuring precise transformations.

The concept of water removal is vital since anhydrides often have different properties and reactions compared to their parent acids.

Inorganic Chemistry

Inorganic chemistry deals with compounds that are not based on carbon-hydrogen bonds. This branch of chemistry plays a significant role in producing and studying an array of substances, including oxides, salts, and anhydrides.

When we talk about acid anhydrides in inorganic chemistry, we're referring to non-carbon based compounds formed typically from the dehydration of acids.

• For instance, \(\mathrm{SO}_{3}\) is an inorganic anhydride derived from \(\mathrm{H}_{2}\mathrm{SO}_{4}\).
• These substances often have varied and application-rich uses in industrial chemistry.
• Understanding these transformations forms a base for more complex inorganic reactions and processes.

Inorganic chemistry provides fundamental insights into material properties and is key to advancements in technology, medicine, and environmental science.