A "flow calorimeter" is used to measure the specific heat of a liquid. Heat is added at a known rate to a stream of the liquid as it passes through the calorimeter at known rate, then a measurement of the resulting temperature difference between the in flow and the out flow points of the liquid stream enables us to compute the specific heat of the liquid. A liquid of density 0.85 `g//cm^(3)` flows through a calorimeter at the rate of 8.0 `cm^(3)//s`. heat is added by means of a 250 watt electric heating coil, and a temperature difference of `15^(@)C` is established in steady state conditions between the in flow and out flow points.
Q. Rate of heat added per second is

Options

A. 4.18 J/s
B. 59.8 cal/s
C. 5 cal/s
D. 90 cal/2

Answer

To solve the problem of determining the rate of heat added per second in a flow calorimeter, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Power of the Heating Coil**:
The power of the electric heating coil is given as 250 watts.

2. **Convert Watts to Joules per Second**:
Since 1 watt is equivalent to 1 joule per second, the heat added per second is:
\[ \text{Heat added} = 250 \text{ watts} = 250 \text{ joules/second} \]

3. **Convert Joules to Calories**:
To convert joules to calories, we use the conversion factor where 1 calorie is approximately equal to 4.18 joules. Therefore, we can convert the heat added per second to calories:
\[ \text{Heat added in calories} = \frac{250 \text{ joules}}{4.18 \text{ joules/calorie}} \approx 59.8 \text{ calories/second} \]

4. **Final Result**:
The rate of heat added per second is approximately:
\[ \text{Rate of heat added} \approx 59.8 \text{ calories/second} \]

### Summary:
The rate of heat added per second in the flow calorimeter is approximately 59.8 calories/second.

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