Questions: A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains 6.30 kg of water at 35.1°C. During the reaction 10 kJ of heat flows out of the flask and into the bath. Calculate the new temperature of the bath. Assume the specific heat capacity of water is 4.185 J/g · °C.
Transcript text: A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains 6.30 kg of water at $35.1^{\circ} \mathrm{C}$. During the reaction $10 \mathrm{~kJ}$ of heat flows out of the flask and into the bath. Calculate the new temperature of the bath. Assume the specific heat capacity of water is $4.185 \frac{J}{g \cdot ^{\circ}C}$.
Solution
Solution Steps
Step 1: Identify the given data
We are given:
Mass of water, \( m = 6.30 \, \text{kg} \)
Initial temperature of water, \( T_i = 35.1^\circ \text{C} \)
Heat added to the water, \( Q = 10 \, \text{kJ} = 10,000 \, \text{J} \)
Specific heat capacity of water, \( c = 4.185 \, \text{J/g}^\circ \text{C} \)
Step 2: Convert mass to grams
Since the specific heat capacity is given in \(\text{J/g}^\circ \text{C}\), we need to convert the mass from kilograms to grams:
\[ m = 6.30 \, \text{kg} \times 1000 \, \text{g/kg} = 6300 \, \text{g} \]
Step 3: Use the heat transfer formula
The formula for heat transfer is:
\[ Q = mc\Delta T \]
where \(\Delta T\) is the change in temperature. We need to solve for \(\Delta T\):
\[ \Delta T = \frac{Q}{mc} \]
Step 4: Calculate the change in temperature
Substitute the given values into the formula:
\[ \Delta T = \frac{10,000 \, \text{J}}{6300 \, \text{g} \times 4.185 \, \text{J/g}^\circ \text{C}} \]
\[ \Delta T = \frac{10,000}{26365.5} \]
\[ \Delta T = 0.3793^\circ \text{C} \]
Step 5: Determine the new temperature
Since the heat flows into the water, the temperature will increase:
\[ T_f = T_i + \Delta T \]
\[ T_f = 35.1^\circ \text{C} + 0.3793^\circ \text{C} \]
\[ T_f = 35.4793^\circ \text{C} \]
Final Answer
The new temperature of the water bath is:
\[
\boxed{T_f = 35.48^\circ \text{C}}
\]