A compound with molcular formula `C_(4)H_(10)O_(3)`. is converted by the action of acetyl chloride to a compound of molecular mass 190. The original compound `(C_(4)H_(10)O_(3))` has

Options

A. one-OH group
B. two-OH groups
C. three-OH groups
D. four-OH groups

Explanation

To solve the problem, we need to analyze the information given about the compound with the molecular formula C4H10O3 and its conversion by acetyl chloride.

### Step-by-Step Solution:

1. **Identify the Original Compound:**
The original compound has the molecular formula C4H10O3. This suggests that it could be a type of alcohol or a polyol, as it contains three oxygen atoms.

2. **Understand the Reaction with Acetyl Chloride:**
The reaction with acetyl chloride (CH3COCl) involves acetylation, where the hydroxyl (OH) group of the alcohol is replaced by an acetyl group (CH3CO). This process typically results in the formation of an ester.

3. **Calculate the Molecular Mass of the Original Compound:**
The molecular mass of C4H10O3 can be calculated as follows:
- Carbon (C): 4 × 12.01 g/mol = 48.04 g/mol
- Hydrogen (H): 10 × 1.008 g/mol = 10.08 g/mol
- Oxygen (O): 3 × 16.00 g/mol = 48.00 g/mol
- Total = 48.04 + 10.08 + 48.00 = 106.12 g/mol

4. **Determine the Molecular Mass of the Product:**
The product formed after the reaction has a molecular mass of 190 g/mol.

5. **Calculate the Change in Molecular Mass:**
When the hydroxyl group (OH) is replaced by the acetyl group (CH3CO), we need to account for the mass change:
- The mass of the hydroxyl group (OH) is approximately 17 g/mol (16 for O and 1 for H).
- The mass of the acetyl group (CH3CO) is approximately 43 g/mol.
- The change in mass due to this substitution is:
\[ \text{Change} = \text{Mass of Acetyl Group} - \text{Mass of Hydroxyl Group} = 43 - 17 = 26 \text{ g/mol} \]

6. **Calculate the Molecular Mass of the Original Compound:**
The molecular mass of the original compound after the substitution should equal the mass of the product:
\[ \text{Molecular Mass of Original Compound} + 26 = 190 \]
Therefore,
\[ \text{Molecular Mass of Original Compound} = 190 - 26 = 164 \text{ g/mol} \]

7. **Conclusion:**
The original compound C4H10O3 has a molecular mass of approximately 106.12 g/mol, which is less than 164 g/mol. This indicates that the original compound is likely a triol (a molecule with three hydroxyl groups), and the reaction with acetyl chloride leads to a product with a higher molecular mass due to the addition of acetyl groups.