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Ethanol (C2H5OH) melts at –114 °C and boils at 78 °C. The enthalpy of fusion of ethanol is 5.02 kJ/mol, and its enthalpy of vapo

alexandr1967 [171]

Answer:

First question

$Q = 36826 \ J$

Second question

$Q = 52299.7 \ J$

Explanation:

From the question we are told that

The melting point of Ethanol is $T_m = -114 ^oC$

The boiling point of Ethanol is $T_b = 78^ oC$

The enthalpy of fusion of Ethanol is $F = 5.02 \ kJ / mol = 5.02 *10^{3}\ kJ / mol$

The enthalpy of vaporization of Ethanol is $L = 38.56 \ kJ / mol = 38.56 *10^{3} \ J / mol$

The specific heat of solid Ethanol is $c_e = 0.97 \ J/ g \cdot K$

The specific heat of liquid Ethanol is $c_l = 2.3 \ J / g \cdot K$

The mass of the Ethanol given is $m = 35.0 \ g$

Considering the first question

The initial temperature is $T_i = 27^oC$

The final temperature is $T_f = 120^oC$

Generally the heat required too raise the Ethanol to its boiling point is mathematically represented as

$Q_1 = m * c_l * (T_b - T_i)$

=> $Q_1 = 35.0 * 2.3 * ( 78 - 27)$

=> $Q_1 =4106 \ J$

Genially the number of moles of Ethanol given is mathematically represented as

$n = \frac{m}{Z}$

Here Z is the molar mass of Ethanol with value $Z = 46 g/mol$

So

$n = \frac{35}{46 }$

=> $n = 0.7609 \ mol$

Generally the heat of vaporization of the Ethanol is mathematically represented as

$Q_2 = n * L$

=> $Q_2 =0.7809 * 38.56 * 10^{3}$

=> $Q_2 =29339 \ J$

Generally the heat required too raise the Ethanol from its boiling point to $T_f$ is mathematically represented as

$Q_3 = m * c_l * (T_f - T_b)$

=> $Q_3 = 35 * 2.3 * (120 - 78 )$

=> $Q_3 = 3381 \ J$

Generally the total heat required is

$Q = Q_1 + Q_2 + Q_3$

=> $Q = 4106 + 29339 + 3381$

=> $Q = 36826 \ J$

Considering the second question

The initial temperature is $T_i = -120^oC$

The final temperature is $T_f = 120^oC$

Generally the heat required too raise the Ethanol to its melting point is mathematically represented as

$Q_1 = m * c_e * (T_m - T_i)$

=> $Q_1 = 35.0 * 0.97 * ( -114 - (- 120) )$

=> $Q_1 = 203.7 \ J$

Generally the heat of fusion of the Ethanol is mathematically represented as

$Q_2 = n * F$

=> $Q_2 =0.7809 * 5.02 *10^{3}$

=> $Q_2 =3920 \ J$

Generally the heat required too raise the Ethanol to its boiling point is mathematically represented as

$Q_3 = m * c_l * (T_b - T_m)$

=> $Q_3 = 35.0 * 2.3 * ( 78 - (- 114) )$

=> $Q_3 =15456 \ J$

Generally the heat of vaporization of the Ethanol is mathematically represented as

$Q_4 = n * L$

=> $Q_4 =0.7809 * 38.56 * 10^{3}$

=> $Q_4 =29339 \ J$

Generally the heat required too raise the Ethanol from its boiling point to $T_f$ is mathematically represented as

$Q_5 = m * c_l * (T_f - T_b)$

=> $Q_5 = 35 * 2.3 * (120 - 78 )$

=> $Q_5 = 3381 \ J$

Generally the total heat required is

$Q = Q_1 + Q_2 + Q_3+Q_4 + Q_5$

=> $Q = 203.7 + 3920 + 15456 +29339+3381$

=> $Q = 52299.7 \ J$

5 0

3 years ago

Determine the molar mass of CuSO4×5H2O

asambeis [7]

248.72 g/mol

CuSO4 has a molar mass of 159.62. H2O has a molar mass of 18.02, which is multiplied by 5 to reflect the 5 H2O molecules.

159.62+5(18.02)=249.72 g/mol

7 0

3 years ago

At constant temperature, when the volume of a gas is decreased, what happens to its pressure? Select one: a. It increases. b. It

natulia [17]

Answer:

The answer would be

a. it increases

3 0

3 years ago

Which of the following is NOT an indication of a chemical reaction?

PolarNik [594]

A. The substance dissolved. Just because a substance dissolved in a solvent doesn’t mean that a chemical action occurred. For example, if you put sugar in water as stir, it will dissolve, but the chemical make up of the sugar and the water don’t change. A chemical reaction can be indicated by a drastic change in color or temperature or if a substance precipitate.

Hope this helped :)

6 0

2 years ago

Read 2 more answers

The mass of an unidentified metal sphere is 133 grams. Students determine the

Rainbow [258]

Given the data from the question, the identity of the unknown metal having a of mass 133 g is Cobalt

<h3>What is density? </h3>

The density of a substance is simply defined as the mass of the subtance per unit volume of the substance. Mathematically, it can be expressed as

Density = mass / volume

<h3>How to determine the density </h3>

Mass = 133 g
Volume of water = 25 mL
Volume of water + metal = 40 mL
Vol of metal = 40 – 25 = 15 mL

Density =?

Density = mass / volume

Density = 133 / 15

Density = 8.86 g/mL

Comparing the density of the unknown metal (i.e 8.86 g/mL) with those given in the chart in the question above, we can conclude that the unknown metal is Cobalt

Learn more about density:

brainly.com/question/952755

4 0

2 years ago