Concentration of alcohol in a sugar solution inoculated with yeast after which yeast gets killed is

Options

A. 0.13
B. 0.25
C. 0.3
D. 0.2

Answer

To solve the question regarding the concentration of alcohol in a sugar solution inoculated with yeast after which the yeast gets killed, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Process of Alcoholic Fermentation**:
- Yeast, when inoculated in a sugar solution, undergoes alcoholic fermentation. During this process, yeast converts sugars into alcohol (ethanol) and carbon dioxide.

2. **Identify the Toxicity of Alcohol to Yeast**:
- As the fermentation process continues, the concentration of alcohol increases. However, alcohol is toxic to yeast cells at certain concentrations.

3. **Determine the Critical Concentration**:
- Research indicates that yeast can survive and ferment sugars up to a certain concentration of alcohol. Beyond this concentration, the alcohol begins to kill the yeast cells.

4. **Find the Threshold Concentration**:
- The threshold concentration of alcohol that is lethal to yeast is approximately 13%. This means that when the concentration of alcohol in the solution reaches about 13%, the yeast will begin to die.

5. **Convert the Percentage to Decimal**:
- To match the options given in the question, we convert 13% into decimal form:
- 13% = 0.13.

6. **Select the Correct Answer**:
- Based on the above analysis, the concentration of alcohol in a sugar solution inoculated with yeast after which the yeast gets killed is 0.13.

### Final Answer:
- The correct answer is **0.13**.

---