Choose the correct increasing order of density of the following compounds.

Options

A. `C_3H_7ClltC_3H_7iltCH_2Cl_2ltCCl_2`
B. `C_3H_7IltC_3H_7ClltCH_2CL_2ltCCl_4`
C. `C_3H_7iltC_3H_7ClltCCl_4ltCH_2Cl_2`
D. `C Cl_34ltCH_2Cl_2ltC_3H_7iltC_3H_7Cl`

Explanation

To determine the correct increasing order of density for the given compounds, we will analyze the factors that affect density and compare the compounds based on their molecular composition.

### Step 1: Understanding Density
Density is defined as mass per unit volume (Density = Mass/Volume). Therefore, the density of a compound is influenced by both its mass and its volume.

### Step 2: Identify the Compounds
We have the following compounds to analyze:
1. C3F7
2. C3F7I
3. CH2Cl2
4. CCl4

### Step 3: Analyze the Components
- **Carbon (C)** has an atomic mass of 12 g/mol.
- **Hydrogen (H)** has an atomic mass of 1 g/mol.
- **Chlorine (Cl)** has an atomic mass of approximately 35.5 g/mol.
- **Fluorine (F)** has an atomic mass of approximately 19 g/mol.
- **Iodine (I)** has an atomic mass of approximately 127 g/mol.

### Step 4: Assess the Number of Halogens and Carbon Atoms
- **C3F7**: Contains 3 Carbon atoms and 7 Fluorine atoms.
- **C3F7I**: Contains 3 Carbon atoms, 7 Fluorine atoms, and 1 Iodine atom.
- **CH2Cl2**: Contains 1 Carbon atom and 2 Chlorine atoms.
- **CCl4**: Contains 1 Carbon atom and 4 Chlorine atoms.

### Step 5: Compare Densities
1. **CCl4** has the highest density due to having 4 Chlorine atoms, which are heavier than Carbon.
2. **CH2Cl2** has 2 Chlorine atoms, which gives it a higher density than C3F7I.
3. **C3F7I** has 3 Carbons and 7 Fluorines, but the presence of 1 Iodine atom (which is heavier than Chlorine) will increase its density, but not as much as CCl4.
4. **C3F7** has the least density because it has no halogen atoms that are heavier than Fluorine.

### Step 6: Conclusion
Based on the analysis, the increasing order of density is:
- C3F7 < C3F7I < CH2Cl2 < CCl4

### Final Answer
Thus, the correct increasing order of density of the compounds is:
**C3F7 < C3F7I < CH2Cl2 < CCl4**