Carbohydrates are compounds containing only carbon, hydrogen and oxygen having the atomic ratio of `H : O` as `2 : 1`. When heated in the absence of air, these compounds decompose to form carbon and water.
a. If `310 g` of a carbohydrates leaves a residue of `124 g` of carbon on heating in absence of air, whatis the empirical formula of the carbohydrate?

Explanation

To find the empirical formula of the carbohydrate based on the given information, we can follow these steps:

### Step 1: Identify the mass of carbon and water produced
- We know that the mass of the carbohydrate is 310 g and the mass of carbon residue after heating is 124 g.
- To find the mass of water produced, we subtract the mass of carbon from the mass of the carbohydrate.

**Calculation:**
\[ \text{Mass of water} = \text{Mass of carbohydrate} - \text{Mass of carbon} \]
\[ \text{Mass of water} = 310 \, \text{g} - 124 \, \text{g} = 186 \, \text{g} \]

### Step 2: Calculate the moles of carbon and water
- Now we need to calculate the number of moles of carbon and water produced.
- The molar mass of carbon (C) is 12 g/mol and the molar mass of water (H₂O) is 18 g/mol.

**Calculation for moles of carbon:**
\[ \text{Moles of carbon} = \frac{\text{Mass of carbon}}{\text{Molar mass of carbon}} = \frac{124 \, \text{g}}{12 \, \text{g/mol}} \approx 10.33 \, \text{moles} \]

**Calculation for moles of water:**
\[ \text{Moles of water} = \frac{\text{Mass of water}}{\text{Molar mass of water}} = \frac{186 \, \text{g}}{18 \, \text{g/mol}} \approx 10.33 \, \text{moles} \]

### Step 3: Determine the mole ratio of carbon to water
- Now we can find the ratio of moles of carbon to moles of water.

**Calculation:**
\[ \text{Ratio of carbon to water} = \frac{10.33}{10.33} = 1:1 \]

### Step 4: Write the empirical formula
- The empirical formula is determined from the ratio of moles of carbon and water. Since we have a 1:1 ratio, we can express the empirical formula as:
\[ \text{Empirical formula} = \text{C}_1\text{H}_2\text{O}_1 = \text{CH}_2\text{O} \]

### Final Answer
The empirical formula of the carbohydrate is **CH₂O**.

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