Is there a difference between heating 50 mL of water to a given temperature, and heating 100 mL of water to the same given temperature but then removing 50 mL?

Yes there is a difference. What specific variable are we observing here?

The amount of thermal energy, the number of water particles, or the speed of the particles

If we are looking at the final 50 mL, then it will be the same in both cases except for the number of water particles. There will be fewer water particles in the final 50 mL of the second situation than the first, because water expands as it heats up.

Yes, there is a difference between heating 50 mL of water to a given temperature and heating 100 mL of water to the same given temperature but then removing 50 mL.

To understand the difference, you need to consider the concept of heat capacity. The heat capacity of a substance is the amount of heat energy required to raise its temperature by a certain amount. In this case, we are dealing with water.

The heat capacity of water is commonly expressed as specific heat, which is the amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius. The specific heat of water is approximately 4.18 J/g°C.

So, let's break down the two scenarios and their outcomes:

1. Heating 50 mL of water to a given temperature:
Suppose you have 50 mL of water and you heat it to a specific temperature. The amount of heat energy required to raise the temperature of the water will be calculated based on the specific heat of water and the mass of the water in grams (since density of water is 1g/mL). You can use the formula Q = m * c * ΔT, where Q is the heat energy, m is the mass in grams, c is the specific heat, and ΔT is the change in temperature.

2. Heating 100 mL of water to the same given temperature and then removing 50 mL:
In this case, you have initially heated 100 mL of water to the same given temperature. However, when you remove 50 mL of the heated water, you are essentially removing half of the mass of water. So the total remaining mass of water would be 50 mL. As a result, when you remove half of the water, you also remove half of the heat energy that was initially added.

In summary, heating 50 mL of water to a given temperature and heating 100 mL of water to the same temperature but then removing 50 mL will result in a difference in the amount of heat energy required. The first scenario only considers the heat energy required for 50 mL of water, whereas the second scenario has an extra step of subtracting half of the water, resulting in less heat energy required.