1 Kcal is about

Options

A. 4.18 J
B. 41.8J
C. 418 J
D. 4180 J

Answer

To solve the question "1 Kcal is about," we need to convert kilocalories to joules. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Definition of Kilocalorie
1 kilocalorie (Kcal) is defined as the amount of energy required to raise the temperature of 1 kilogram of water by 1 degree Celsius.

### Step 2: Convert Kilocalories to Calories
1 kilocalorie is equal to 1000 calories (cal). This is a straightforward conversion based on the definition of kilocalories.

### Step 3: Convert Calories to Joules
We know from physics that:
1 calorie = 4.18 joules (J).

### Step 4: Calculate the Total Joules in 1 Kilocalorie
To find out how many joules are in 1 kilocalorie, we multiply the number of calories in a kilocalorie by the number of joules in a calorie:
- 1 Kcal = 1000 cal
- Therefore, 1 Kcal = 1000 cal × 4.18 J/cal

### Step 5: Perform the Calculation
Now, we perform the multiplication:
1 Kcal = 1000 × 4.18 J = 4180 J.

### Conclusion
Thus, 1 kilocalorie is equal to 4180 joules.

### Final Answer
1 Kcal is about 4180 joules.

---