Answered

Get reliable answers to your questions at Westonci.ca, where our knowledgeable community is always ready to help. Join our platform to connect with experts ready to provide precise answers to your questions in different areas. Our platform offers a seamless experience for finding reliable answers from a network of knowledgeable professionals.

How much energy is released when 2.65kg of diethyl ether ((C2H5)2O) freezes? The heat of fusion for diethyl ether is 7.27 kJ/mol.

Sagot :

Yipes
m=2.65kg=2650g
M=74g/mol

n = m/M = 2650g/74g/mol ≈ 35.81mol

Heat of fusion = 7.27kJ/mol

If            7.27kJ -------------  energy is in  --------------- 1mol
than           x      -------------  energy is in  --------------- 35.81mol

x = [35.81mol*7.27kJ]/1mol = 260.3387kJ

The amount of energy released when [tex]{{\text{(}}{{\text{C}}_2}{{\text{H}}_5}{\text{)}}_2}{\text{O}}[/tex] freezes is [tex]\boxed{{\text{259}}{\text{.92 kJ}}}[/tex].

Further explanation:

Heat of fusion measures the amount of energy needed to heat given mass of a solid to change its state into liquid. Also, it represents the amount of energy given up when a given mass of liquid solidifies.

When a substance converts from its phase from solid to liquid, the change in enthalpy [tex]\left({\Delta H}}}\right)[/tex] is positive, and if the substance transforms from liquid state to solid state then the change in enthalpy[tex]\left({\Delta H}}}\right)[/tex] is negative.

The expression to relate the energy released and heat of solidification is as follows:

[tex]{\text{Energy released}}={\text{n}}\times\left({{\Delta }}{{\text{H}}_{{\text{solidification}}}}}\right)[/tex]

Given mass of [tex]{{\text{(}}{{\text{C}}_2}{{\text{H}}_5}{\text{)}}_2}{\text{O}}[/tex] is 2.65 kg.

The conversion factor to convert mass in (g) from (kg) is written as follows:

[tex]{\text{1kg}}=1000\;{\text{g}}[/tex]

So, 2.65 kg of mass is converted into (g) as follows:

[tex]\begin{aligned}{\text{Mass}}&=\,\left({2.65\;{\text{kg}}} \right)\left( {\frac{{{\text{1000}}\;{\text{g}}}}{{{\text{1}}\;{\text{k}}{\text{g}}}}}\right)\\&={\text{2650 g}}\\\end{aligned}[/tex]

Molar mass of [tex]{{\text{(}}{{\text{C}}_2}{{\text{H}}_5}{\text{)}}_2}{\text{O}}[/tex] is 74.12 g/mol.

The moles of [tex]{{\text{(}}{{\text{C}}_2}{{\text{H}}_5}{\text{)}}_2}{\text{O}}[/tex]can be calculated as follows:

[tex]\begin{aligned}{\text{number of moles }}&=\frac{{{\text{mass of (}}{{\text{C}}_2}{{\text{H}}_5}{{\text{)}}_2}{\text{O}}}}{{{\text{molar mass of (}}{{\text{C}}_2}{{\text{H}}_5}{{\text{)}}_2}{\text{O}}}}\\&=\frac{{{\text{2650 g}}}}{{{\text{74}}{\text{.12}}\;{\text{g/mol}}}}\\&=35.752{\text{ mol}}\\\end{aligned}[/tex]

The heat of fusion for diethyl ether[tex]{{\text{(}}{{\text{C}}_2}{{\text{H}}_5}{\text{)}}_2}{\text{O}}[/tex]is 7.27 kJ/mol and therefore the heat of solidification for diethyl ether[tex]{{\text{(}}{{\text{C}}_2}{{\text{H}}_5}{\text{)}}_2}{\text{O}}[/tex]is -7.27 kJ/mol.

The formula to calculate the amount of energy released is as follows:

[tex]{\text{Amount of energy}}={\text{number of moles}}\times{\Delta }}{{\text{H}}_{{\text{solidification}}}}{\text{ }}[/tex]        …… (1)

Substitute 35.752 mol for number of moles and -7.27 kJ/mol for [tex]{\Delta }}{{\text{H}}_{{\text{solidification}}}}[/tex] in the equation (1).

[tex]\begin{aligned}{\text{Amount of energy}}&=\left({35.752\;{\text{mol}}}\right)\left({-7.27{\text{kJ/mol}}}\right)\\&=-259.92{\text{ kJ}}\\\end{aligned}[/tex]

Therefore, the amount of energy released is [tex]{\mathbf{259}}{\mathbf{.92 kJ}}[/tex].

Learn more:

1. Determine the coefficients are needed to balance the equation for the complete combustion of methane? https://brainly.com/question/1971314

2. Determine the energy required to break the hydrogen bond?https://brainly.com/question/10278354

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Thermodynamics

Keywords: Heat of fusion, number of moles, enthalpy, enthalpy change, released, absorbed, 259.91 kJ, 7.27kJ/mol, and 35.752 mol.