0.25 g of an organic compound 'X' containing carbon, hydrogen and oxygen was analysed by the combustion method. The increase in mass of calcium chloride tube and potash bulbs at the end of the experiment was found to be 0.15 g and 0.1837 g respectively. Calculate the percentage composition of the compound.

Explanation

To calculate the percentage composition of the organic compound 'X' containing carbon, hydrogen, and oxygen, we will follow these steps:

### Step 1: Determine the mass of carbon in the compound
The increase in mass of the potash bulb indicates the mass of carbon dioxide (CO2) produced during combustion. The increase in mass is given as 0.1837 g.

To find the mass of carbon:
1. The molar mass of CO2 = 12 (C) + 16*2 (O) = 44 g/mol.
2. The mass of carbon in CO2 can be calculated using the ratio of the molar mass of carbon to the molar mass of CO2:
\[ \text{Mass of Carbon} = \left(\frac{12 \text{ g/mol}}{44 \text{ g/mol}}\right) \times 0.1837 \text{ g} \]
\[ \text{Mass of Carbon} = 0.0500 \text{ g} \]

### Step 2: Determine the mass of hydrogen in the compound
The increase in mass of the calcium chloride tube indicates the mass of water (H2O) produced during combustion. The increase in mass is given as 0.15 g.

To find the mass of hydrogen:
1. The molar mass of H2O = 2*1 (H) + 16 (O) = 18 g/mol.
2. The mass of hydrogen in H2O can be calculated using the ratio of the molar mass of hydrogen to the molar mass of H2O:
\[ \text{Mass of Hydrogen} = \left(\frac{2 \text{ g/mol}}{18 \text{ g/mol}}\right) \times 0.15 \text{ g} \]
\[ \text{Mass of Hydrogen} = 0.0167 \text{ g} \]

### Step 3: Calculate the mass of oxygen in the compound
To find the mass of oxygen, we can use the total mass of the compound and subtract the masses of carbon and hydrogen:
\[ \text{Mass of Oxygen} = \text{Total Mass} - (\text{Mass of Carbon} + \text{Mass of Hydrogen}) \]
\[ \text{Mass of Oxygen} = 0.25 \text{ g} - (0.0500 \text{ g} + 0.0167 \text{ g}) = 0.1833 \text{ g} \]

### Step 4: Calculate the percentage composition of each element
1. **Percentage of Carbon**:
\[ \text{Percentage of Carbon} = \left(\frac{0.0500 \text{ g}}{0.25 \text{ g}}\right) \times 100 = 20.00\% \]

2. **Percentage of Hydrogen**:
\[ \text{Percentage of Hydrogen} = \left(\frac{0.0167 \text{ g}}{0.25 \text{ g}}\right) \times 100 = 6.68\% \]

3. **Percentage of Oxygen**:
\[ \text{Percentage of Oxygen} = \left(\frac{0.1833 \text{ g}}{0.25 \text{ g}}\right) \times 100 = 73.32\% \]

### Final Result
- Percentage of Carbon = 20.00%
- Percentage of Hydrogen = 6.68%
- Percentage of Oxygen = 73.32%