Question

A chemical reaction occurs in an acid medium while balancing the ionic equation for such reaction to balance oxygen atoms we add (1) ${\mathrm{O}}_2$ (2) ${\mathrm{H}}_2\mathrm{O}$ (3) $\mathrm{OH}$ (4) ${\mathrm{H}}_2{\mathrm{SO}}_4$

Short answer

To balance oxygen atoms in acidic medium, add ${\mathrm{H}}_2\mathrm{O}$.

Step-by-step solution

Understand the Environment

The reaction occurs in an acid medium. In acidic conditions, certain substances are used to balance the equation properly.

Identify the Requirement

The goal is to balance oxygen atoms in the ionic equation. This is typically done by determining which molecule adds or removes oxygen appropriately.

Analyze the Options

Review the options provided: (1) ${\mathrm{O}}_2$ - molecular oxygen, not typically used directly in balancing. (2) ${\mathrm{H}}_2\mathrm{O}$ - water, often used in balancing oxygen. (3) OH - Hydroxide ion, used in basic medium not acidic. (4) ${\mathrm{H}}_2{\mathrm{SO}}_4$ - sulfuric acid, provides H+ but not used for balancing oxygen.

Choose the Correct Molecule

Since the question asks how to balance oxygen atoms in an acidic medium: ${\mathrm{H}}_2\mathrm{O}$ (water) is commonly used to balance oxygen atoms in acidic reactions.

Key concepts

acidic medium

In chemistry, understanding the environment where a reaction takes place is crucial. An acidic medium means the solution has excess $H^{+}$ ions. In such conditions, certain rules and substances are applied to balance chemical equations. Acidic mediums are characterized by a pH less than 7. When we say an equation needs to be balanced in an acidic medium, we align the atoms and charges using the special properties of acids. In these environments, we commonly use hydrogen ions $H^{+}$ and water $H_{2}O$ in the balancing process.
Identifying it's an acidic medium helps to apply the correct balancing strategy.

oxygen balancing

Balancing oxygen atoms in a chemical equation, especially in an acidic medium, requires precision. Oxygen atoms can be balanced by adding appropriate molecules where needed. In acidic conditions, the typical species used to balance oxygen is water $H_{2}O$.
Here's why it makes sense:

• Water contains both oxygen and hydrogen, which enables it to effectively balance oxygen atoms while also contributing to hydrogen atom balance.
• Molecular oxygen ($O_2$) is not typically added directly in ionic equations for balancing.
• Hydroxide ions ($O{H}^{-}$) are used in basic mediums, not acidic ones.
• While sulfuric acid ($H_{2}S{O}_4$) provides $H^{+}$ ions, it’s not used specifically for balancing oxygen atoms.

ionic equations

Ionic equations represent the reactions of ions in solution. They are often simplified versions of overall chemical reactions, focusing on ions that participate. These equations break down substances into their ionic components, revealing the true chemical behavior in the medium. For balancing, we must:

• Ensure both atom counts and charges are balanced.
• Add $H^{+}$ ions in acidic mediums to balance hydrogen.
• Use water $H_{2}O$ to balance oxygen atoms.

By converting to ionic equations, we highlight the primary species that partake in the reaction, making it simpler to identify what needs to be added to achieve balance.

chemical reactions

Chemical reactions involve the transformation of reactants into products. They rearrange atoms and ions, leading to new substances. Properly balancing these reactions is essential for understanding how matter and energy are conserved. Steps to balance any chemical reaction include:

• Write down the unbalanced equation.
• Break compounds into their ionic or molecular forms if dealing with ionic equations.
• Count the number of atoms for each element on both sides.
• Use appropriate species (like water in acidic mediums) to balance.
• Repeat for each element until the equation is balanced.
• Readjust for both atoms and charges where needed.

Balancing ensures conservation laws are followed, aligning with physical realities of reaction mechanisms.