A. it can be modified or rejected
The correct answer is option C. <span>This is a demonstration of Boyle’s law. As the volume increases, the pressure decreases, and the marshmallow will grow larger.
</span><span>
Keisha follows the instructions for a demonstration on gas laws.
1. Place a small marshmallow in a large plastic syringe.
2. Cap the syringe tightly.
3. Pull the plunger back to double the volume of gas in the syringe.
Now, this activity is being done at the same temperature, because there is no mention of the temperature change. Thus, when the plunger is pulled back, the volume doubles, so pressure will decrease. Therefore, </span>This is a demonstration of Boyle’s law. As the volume increases, the pressure decreases, and the marshmallow will grow larger.
6.35x10^-4 OR 6.3x10-4 (if only one decimal number is allowed)
Answer:
The mass rate of the cooling water required is: 
Explanation:
First, write the energy balance for the condensator: The energy that enters to the equipment is the same that goes out from it; consider that there is no heat transfer to the surroundings and kinetic and potential energy changes are despreciable.
Where w refers to the cooling water and s to the steam flow. Reorganizing,
Write the difference of enthalpy for water as Cp (Tout-Tin):
This equation will let us to calculate the mass rate required. Now, let's get the enthalpy and Cp data. The enthalpies can be read from the steam tables (I attach the tables I used). According to that, 
and 
can be calculated as:
.
The Cp of water at 25ºC (which is the expected average temperature for water) is: 4.176 
. If the average temperature is actually different, it won't mean a considerable mistake. Also we know that 
, so let's work with the limit case, which is 
to calculate the minimum cooling water mass rate required (A higher one will give a lower temperature difference as a result). Finally, replace data:
