Question

3. How much energy is needed to raise 45 grams of water from 40°C to 115 °C?

The specific heat capacity of ice is 2.06 J/g °C

The specific heat capacity of water is 4.18 J/g °C

The specific heat capacity of steam is 2.02 J/g °C

The heat of fusion of water is 334 J/g

The heat of vaporization of water is 2260 J/g.

Answer 1

Q = 114349.5 J

Step-by-step explanation:

Hello there!

In this case, since this a problem in which we need to calculate the total heat of the described process, it turns out convenient to calculate it in three steps; the first one, associated to the heating of the liquid water from 40 °C to 100 °C, next the vaporization of liquid water to steam at constant 100 °C and finally the heating of steam from 100 °C to 115 °C. In such a way, we calculate each heat as shown below:

`Q_1=45g*4.18(J)/(g\°C)*(100\°C-40\°C)=11286J\\\\Q_2=45g* 2260 (J)/(g) =101700J\\\\Q_3=45*2.02(J)/(g\°C)*(115\°C-100\°C)=1363.5J`

Thus, the total energy turns out to be:

`Q_T=11286J+101700J+1363.5J\\\\Q_T=114349.5J`

Best regards!