Composition of borax (Tincal) is

Options

A. `Na_2B_(4)O_(7).4H_(2)O`
B. `Na_(2)B_(4)O_(7).10H_(2)O`
C. `NaBO_(2)`
D. `Na_(2)BO_(3)`

Answer

To determine the composition of borax (also known as tincal), we can follow these steps:

### Step 1: Identify the Chemical Formula
Borax is commonly known by its chemical formula. The most recognized formula for borax is Na2B4O7·10H2O. This indicates that borax is a hydrated sodium borate.

### Step 2: Breakdown the Formula
The formula Na2B4O7·10H2O can be broken down as follows:
- **Na2**: This indicates that there are two sodium (Na) ions.
- **B4**: This indicates that there are four boron (B) atoms.
- **O7**: This indicates that there are seven oxygen (O) atoms in the borate part.
- **10H2O**: This indicates that there are ten water molecules associated with the compound, which makes it a hydrate.

### Step 3: Understanding the Composition
Borax can also be represented in different forms, such as:
- Na2B4O5(OH)·8H2O, which shows a different hydration state and hydroxyl group.
- Other forms like Na2B4O7·4H2O and Na2BO2, but the most common and recognized form is Na2B4O7·10H2O.

### Step 4: Conclusion
Thus, the primary composition of borax (tincal) is Na2B4O7·10H2O.

### Final Answer
The composition of borax (tincal) is Na2B4O7·10H2O.

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