To find the most likely final temperature of the mixture, we need to understand what happens when two volumes of water at different temperatures are mixed together. Since the volumes of water being mixed are equal and assuming there is no heat lost to the surroundings, the final temperature of the mixture will be the average of the initial temperatures.
Here is a step-by-step explanation:
1. Measure the amount of water in each vessel and their initial temperatures. We have 800 mL of water at 20°C and 800 mL of water at 80°C.
2. Calculate the average of the two initial temperatures. The average is calculated by adding the temperatures together and dividing by the number of temperatures you are averaging. In our case:
\( \text{average temperature} = \frac{\text{Temperature of first volume} + \text{Temperature of second volume}}{2} \)
3. Plug in the values for the temperatures:
\( \text{average temperature} = \frac{20°C + 80°C}{2} \)
\( \text{average temperature} = \frac{100°C}{2} \)
\( \text{average temperature} = 50°C \)
So, the most likely final temperature of the mixture, when 800 mL of water at 20°C is mixed with 800 mL of water at 80°C, is 50°C.
Therefore, the correct choice is A. 50°C.
