Question

The required heat energy to convert 500ml of water completely to vapour is .....

Answer 1

Hello Dear.

Here is the answer---


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Given---

Volume of the Water = 500 ml
                                 = 0.5 Liter.

Converting liter into m³,
           
          1 m³ = 100 l
⇒ 0.5 l = 0.5/100 m³
            = 0.005 m³

Density of the Water = 1000 kg/m³

Using the Formula,

      Density = Mass/Volume
     Mass = Density × Volume
     Mass = 1000 × 0.005
              = 5 kg.

Since, the Initial Temperature of the Water is not given. Thus, Let the Temperature of the Water be 100°C.

Using the Formula,

    Amount of Heat energy Required = Mass × Latent heat of Vaporization.
                         ⇒ Q = m × L

Latent heat of Vaporization of Water = 2260 J/kg.

     ⇒  Q = 5 × 2260
              = 11300 J

Thus, the amount of Heat energy required to convert Water at 100° C into vapor is 11300 Joules.

If the Initial Temperature of the Water will be given, then You can calculate the Total heat as---

Amount of Heat energy required to bring the water from temperature t to 100 °C
 
=  mass × Spec. Heat Capacity × Change in temperature.
= m × c × Δt

Thus, Total Heat  = mcΔt + Q

By this formula, Total amount of heat can be easily calculated.



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Hope it helps.

Have a Marvelous day.

Answer 2

Answer:

270 k cal

Explanation:

Given mass= 500 ml

in litres = 500/1000 =0.5 l

Latent heat of vaporization= 540 k cal

Q= ml

=0.5× 540

= 270 k cal