The percentage of Se in peroxides enzyme is 0.5% by mass (atomic mass of Se = 78.4 amu). Then , the minimum molecular mass of enzyme which contains not more than one Se atom is

Options

A. `1.568 xx10^4` amu
B. `1.568 xx10^7` amu
C. `1.568 xx10^3` amu
D. `1.568 xx10^6` amu

Answer

To find the minimum molecular mass of the enzyme that contains not more than one selenium (Se) atom, we can follow these steps:

### Step 1: Understand the given information
- Percentage of Se in the enzyme = 0.5% by mass
- Atomic mass of Se = 78.4 amu

### Step 2: Set up the equation
The percentage by mass of an element in a compound is given by the formula:

\[ \text{Percentage of element} = \left( \frac{\text{mass of element}}{\text{molar mass of compound}} \right) \times 100 \]

In this case, we can rearrange the formula to find the molar mass of the enzyme (W):

\[ 0.5 = \left( \frac{78.4}{W} \right) \times 100 \]

### Step 3: Rearranging the equation
Rearranging the equation to solve for W gives:

\[ W = \frac{78.4 \times 100}{0.5} \]

### Step 4: Calculate W
Now, we can calculate W:

\[ W = \frac{7840}{0.5} = 15680 \text{ amu} \]

### Step 5: Conclusion
The minimum molecular mass of the enzyme, which contains not more than one Se atom, is **15680 amu**.

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