Question

How much energy is released when 65.8 g of water freezes

Answer 1

The amount of energy released is calculated by the product of heat of fusion and mass. The formula of amount energy released is given by: $q= L\times m$                (1)

Here,  

q is amount of energy released L is heat of fusion ($334 J/g$) m is mass of water Put all the given values in equation (1)

$q= 334 J/g \times 65.8 g$

$q= 21977.2 Joules$ ≅ $21977 Joules$

$q= 21977 Joules$

Thus, amount of energy released is $21977 Joules$

Answer 2

The amount of heat release to freeze 65.8 g liquid water is $\boxed{-{\text{21}}{\text{.98 kJ}}}$.

Further explanation:

Latent heat  

The heat released or absorbed during the process of conversion physical state of a substance without altering the temperature is known as the latent heat.

In other words, when the physical state changes from liquid phase to solid phase without altering the temperature then the amount of heat released in this process is known as the latent heat fusion.

The formula to calculate heat released from the latent heat of fusion is,

${\text{q}}={\text{m}}{{\text{H}}_{\text{f}}}$     …… (1)

Here,

q is heat released.

m is mass of substance.

${{\text{H}}_{\text{f}}}$is latent heat of fusion.

The mass of given liquid water is 65.8 g.

The latent heat of fusion for freezing process of water is -334 J/g.

Substitute 65.8 g for m and -334 J/g for ${{\text{H}}_{\text{f}}}$ in equation (1) as follows:

$\begin{aligned}{\text{q}}&={\text{m}}{{\text{H}}_{\text{f}}}\\&=\left({65.8{\text{ g}}}\right)\left({-334{\text{ J/g}}}\right)\\&=-21977.2{\text{ J}}\\\end{aligned}$

Here negative sign shows that heat is released in the process.

The heat released to freeze 65.8 g liquid water is 21977.2 J.

The heat released in kilojoule is,

$\begin{aligned}{\text{q}}&=\left({-21977.2{\text{ J}}}\right)\left({\frac{{1{\text{ kJ}}}}{{1000{\text{ J}}}}}\right)\\&=-21.9772{\text{ kJ}}\\&\approx-{\text{21}}{\text{.98 kJ}}\\\end{aligned}$

Learn more:

1. The difference between heat and temperature.:brainly.com/question/914750

2. Determine the process by which water enters into atmosphere?: brainly.com/question/2037060

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Thermodynamics

Keywords: Latent, Heat, fusion, Latent heat of fusion, temperature, ice, water, vapors, equilibrium, heat required, heat released melting, heat release, heat absorbed, 21.98 kJ.