Question

When borax is treated with mineral acids, the product formed is (1) Boron oxide (2) Orthoboric acid (3) Metaboric acid (4) Pyroboric acid

Short answer

The product formed is Orthoboric acid.

Step-by-step solution

Understanding Borax Treatment

First, understand what happens when borax (Na2B4O7·10H2O) reacts with mineral acids like HCl or H2SO4.

Identify the Reaction

When borax is treated with an acid, a double decomposition reaction occurs in which boric acid (H3BO3) is formed.

Final Product Formation

Recognize that orthoboric acid or boric acid is the correct term for H3BO3. Therefore, orthoboric acid is formed.

Matching the Correct Option

Among the given options, identify that option (2) Orthoboric acid is the correct answer.

Key concepts

double decomposition reaction

A double decomposition reaction is a type of chemical reaction where two compounds exchange ions to form two new compounds. This reaction typically occurs between an ionic compound and either another ionic compound or an acid.
For example, when borax (Na2B4O7·10H2O) reacts with a mineral acid like hydrochloric acid (HCl), the ions in both reactants swap places. In this specific reaction, ions from borax and HCl exchange to form sodium chloride (NaCl) and orthoboric acid (H3BO3).
This is why the reaction between borax and mineral acids is considered a double decomposition reaction.
Understanding this type of reaction is crucial for predicting the products of reactions involving ionic compounds and acids.

orthoboric acid formation

Orthoboric acid, also known as boric acid with the chemical formula H3BO3, forms through the double decomposition reaction of borax with a mineral acid.
When borax reacts with an acid, the chemical reaction results in the formation of orthoboric acid and a salt. In the given exercise, borax reacts with hydrochloric acid (HCl) as follows:
a)Reaction:Na2B4O7·10H2O (Borax) + 2HCl → 4H3BO3 (Orthoboric acid) + 2NaCl + 5H2O
Orthoboric acid has various applications, including as an antiseptic, insecticide, and flame retardant. It’s a weak acid with low toxicity, making it suitable for many household uses.
Understanding this formation process helps students grasp how common laboratory and household chemicals can produce useful compounds.

chemical reactions in inorganic chemistry

Inorganic chemistry deals with chemical reactions that typically do not involve carbon-hydrogen bonds, focusing instead on inorganics like salts, metals, and acids.
In the context of borax reacting with acids, we see elements like sodium (Na), boron (B), oxygen (O), and hydrogen (H) participating in reactions that lead to the formation of different compounds.
Learning about chemical reactions in inorganic chemistry helps in understanding the behavior of these elements and compounds under different conditions. Among such reactions are:

• Synthesis Reactions
• Decomposition Reactions
• Single Replacement Reactions
• Double Decomposition (or Replacement) Reactions

Mastering these types of reactions provides a solid foundation for further studies and applications in chemistry, including in fields like materials science, pharmaceuticals, and environmental science.