Question

1. Calculate the amount of energy absorbed when 10 g water at 86 C turns completely to steam vapor at 100C



2. Calculate the amount of energy released when 10 g water at 72 C freezes completely at 0C

Answer 1

Answer:

The amount of energy absorbed when 10 g water at 86 C turns completely to steam vapor at 100 C is 584.76 J

The amount of energy released when 10 g water at 72 C freezes completely at 0 C is 3,012.48 J

Explanation:

Sensible heat is the amount of heat that a body can receive without affecting its molecular structure. If the molecular structure does not change, the state (solid, liquid, gas) does not change. Since the molecular structure does not change, a change in temperature is observed.

In other words, the heat that produces a change in the temperature of a substance without any changes in its physical state (phase change) is called sensible heat.

The equation that allows calculating this type of heat exchange is:

Q = c * m * ΔT

where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the change in temperature.

1. In this case, you know:

• c= 4.184 $\frac{J}{C*g}$
• m= 10 gr
• ΔT=Tfinal - Tinitial= 100 C- 86 C=14 C

Replacing:

Q= 4.184 $\frac{J}{C*g}$ *10 g*14 C

Solving:

Q= 584.76 J

The amount of energy absorbed when 10 g water at 86 C turns completely to steam vapor at 100 C is 584.76 J

2. In this case, you know:

• c= 4.184 $\frac{J}{C*g}$
• m= 10 gr
• ΔT=Tfinal - Tinitial= 0 C- 72 C= -72 C

Replacing:

Q= 4.184 $\frac{J}{C*g}$ *10 g*(-72) C

Solving:

Q= -3,012.48 J

The amount of energy released when 10 g water at 72 C freezes completely at 0 C is 3,012.48 J