Respuesta :


There are two types of heat transfers in this process that are as follows:

q1= heat required to warm the water from 100 °C to 100.0 °C.

q2= heat required to vapourize the water into steam at 100 °C.

c=specific heat of water= 4.184 J g⁻¹ °c⁻¹

m=mass of water=9 g

∆Hvap=enthalpy of vapourisation

ΔT=temperature difference

q1=mcΔT=9  × 4.184 J ×0=0 J

q2=mΔHvap= 9 g × 0.0407 J=0.3663 J

q1+q2= (0 + 0.3663) J  

= 3.6 × 10⁻¹  J  

=  3.6 × 10⁻¹ J

Answer : The heat required will be, 20.35 KJ

Explanation : Given,

Molar mass of [tex]H_2O[/tex] = 18 g/mole

First we have to calculate the moles of [tex]H_2[/tex]

[tex]\text{Moles of }H_2=\frac{\text{Mass of }H_2}{\text{Molar mass of }H_2}=\frac{9g}{18g/mole}=0.5mole[/tex]

Now we have to calculate the heat produced.

Formula used :

[tex]Q=n\times \Delta H_{vap}[/tex]

where,

Q = heat required = ?

n = moles of water = 0.5 mole

[tex]\Delta H_{vap}[/tex] = 40.7 KJ/mole

Now put all the given values in this formula, we get the heat required.

[tex]Q=0.5mole\times 40.7KJ/mole=20.35KJ[/tex]

Therefore, the heat required will be, 20.35 KJ