Degree of unsturation in `C_yH_8` is two. The value of y is….........

Answer

To find the value of \( y \) in the molecular formula \( C_yH_8 \) given that the degree of unsaturation is 2, we can follow these steps:

### Step 1: Understand the Degree of Unsaturation
The degree of unsaturation (DBE) indicates the number of rings and/or multiple bonds (double or triple bonds) in a compound. The formula to calculate the degree of unsaturation is:

\[ DBE = C + 1 - \frac{H + X - N}{2} \]

Where:
- \( C \) = number of carbon atoms
- \( H \) = number of hydrogen atoms
- \( X \) = number of halogen atoms (if any)
- \( N \) = number of nitrogen atoms (if any)

### Step 2: Substitute Known Values
In our case, we have:
- \( H = 8 \)
- \( DBE = 2 \)
- \( C = y \)

Substituting these values into the DBE formula gives:

\[ 2 = y + 1 - \frac{8}{2} \]

### Step 3: Simplify the Equation
Now, simplify the equation:

\[ 2 = y + 1 - 4 \]

This can be rearranged to:

\[ 2 = y - 3 \]

### Step 4: Solve for \( y \)
Now, solve for \( y \):

\[ y = 2 + 3 \]
\[ y = 5 \]

### Conclusion
The value of \( y \) is 5, which means the molecular formula is \( C_5H_8 \).

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