How Much Energy Is Needed to Convert 500 g of Water at 20°C to Steam at 100°C?

In summary, the amount of energy required to transform 500 g of liquid water at 20 degrees Celsius to steam at 100 degrees Celsius can be calculated using the specific heat capacity of liquid water and the latent heat of vaporization for water. Two equations, mct and mLv, can be used to determine the amount of energy needed for heating and evaporation respectively.
  • #1
hackz
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Homework Statement



How much energy does it take to transform 500 g (0.5kg) of liquid water at 20 oC to steam at 100 oC? Note that the specific heat capacity of liquid water is 4.28x10^3 J/Kg/oC and the latent heat of vaporization for water is 2.3x10^6 J/Kg.

Homework Equations


Eh=mct ; m1c1t1=-m2c2t2 ; Eh = mLf ; Eh= mLv


The Attempt at a Solution



no clue..please help..
 
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  • #2
Two steps. first the water needs to be heated to 100 C, then the water has to evaporate. Both steps involve heat going into the water. Which two of those 4 equations do you need?

By the way, in the first and second equation you list, it is not "T" but "change in T." (The triangle, "delta," means "change in...")
 
  • #3


I can provide you with a solution to this problem using the given information and relevant equations. First, we need to calculate the energy required to raise the temperature of 500 g (0.5 kg) of liquid water from 20 oC to 100 oC. This can be done using the equation Eh = mct, where m is the mass of the substance, c is the specific heat capacity, and t is the change in temperature. Plugging in the values, we get:

Eh = (0.5 kg)(4.28x10^3 J/Kg/oC)(100 oC - 20 oC)
= 1.5x10^5 J

Next, we need to calculate the energy required to vaporize the liquid water at 100 oC into steam at the same temperature. This can be done using the equation Eh = mLv, where m is the mass of the substance and Lv is the latent heat of vaporization. Plugging in the values, we get:

Eh = (0.5 kg)(2.3x10^6 J/Kg)
= 1.15x10^6 J

Finally, we can add the two energies together to get the total energy required to transform 500 g of liquid water at 20 oC to steam at 100 oC:

Total energy = 1.5x10^5 J + 1.15x10^6 J
= 1.3x10^6 J

Therefore, it takes 1.3x10^6 J of energy to transform 500 g of liquid water at 20 oC to steam at 100 oC. I hope this helps you with your homework question. Remember to always use the correct equations and units when solving scientific problems.
 

FAQ: How Much Energy Is Needed to Convert 500 g of Water at 20°C to Steam at 100°C?

What is the process of transforming water into steam to produce energy?

The process of transforming water into steam to produce energy is called steam generation. It involves heating water in a boiler until it reaches its boiling point, causing it to turn into steam. The steam is then used to power turbines which in turn generate electricity.

How does water turn into steam?

Water turns into steam when it is heated to its boiling point. The molecules in water gain enough energy to break free from their liquid state and become a gas, forming steam. This process is known as vaporization or boiling.

How much energy can be produced from water to steam conversion?

The amount of energy produced from water to steam conversion depends on several factors such as the amount of water, the temperature and pressure of the steam, and the efficiency of the conversion process. On average, one pound of steam can produce approximately 1,000 BTUs (British Thermal Units) of energy.

What are the advantages of using water to steam energy?

There are several advantages of using water to steam energy. It is a renewable source of energy, as water is constantly replenished through the water cycle. It is also a clean source of energy, as the only byproduct of the conversion process is water vapor. Additionally, steam can be easily transported and used in various applications such as electricity generation, heating, and industrial processes.

Are there any environmental concerns associated with water to steam energy?

While water to steam energy is generally considered a clean source of energy, there are some environmental concerns associated with it. The process of steam generation can release pollutants into the atmosphere if not properly controlled. The disposal of wastewater from the steam generation process can also have negative impacts on the environment. However, these concerns can be mitigated through proper regulations and technologies.

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