HELP !!!!!!! Please !!!!!!!

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

2 years ago

What is the molarity of an HCl solution if 43.6 mL of a 0.125 M NaOH solution are needed to titrate a 25.0 mL sample of the acid

Sveta_85 [38]

Answer: The molarity of an HCl solution is 0.218 M if 43.6 mL of a 0.125 M NaOH solution are needed to titrate a 25.0 mL sample of the acid.

Explanation:

Given: $V_{1}$ = 43.6 mL, $M_{1}$ = 0.125 M

$V_{2}$ = 25.0 mL, $M_{2}$ = ?

Formula used to calculate the concentration of acid is as follows.

$M_{1}V_{1} = M_{2}V_{2}$

Substitute the values into above formula.

$M_{1}V_{1} = M_{2}V_{2}\\0.125 M \times 43.6 mL = M_{2} \times 25.0 mL\\M_{2} = 0.218 M$

Thus, we can conclude that the molarity of an HCl solution is 0.218 M if 43.6 mL of a 0.125 M NaOH solution are needed to titrate a 25.0 mL sample of the acid.

3 0

2 years ago

H2(g)+p4(s)ph3(g) what the answer ?

disa [49]

Answer:

6H2 + P4→ 4PH3

Explanation:

Phosphorus has 4 in it and hydrogen has 3 in it. in order to balance it, we have to put 4 in front of phosphine so that the phosphorus on the product side has an equal amount as to the one on the reactant side.

the only one left to balance is hydrogen and so in order to balance it we put a 6 on h2 because the hydrogen in the product size becomes 12 (4 * 3).

therefore the hydrogen on the reactant side becomes 12 as well (6 * 2)

8 0

3 years ago

Suppose you want to separate a mixture of the following compounds: salicylic acid, 4-ethylphenol, p-aminoacetophenone, and napth

Elodia [21]

Answer:

The procedure you will use in this exercise exploits the difference in acidity and solubility just described.

(a) you will dissolve your unknown in ethyl acetate (an organic solvent). All of the possible compounds are soluble in ethyl acetate.

(b) you will extract with sodium bicarbonate to remove any carboxylic acid that is present.

(c) you will extract with sodium hydroxide to remove any phenol that is present.

(d) you will acidify both of the resulting aqueous solutions to cause any compounds that were extracted to precipitate.

6 0

3 years ago

What is 8S8 <br><br> In need for a quick answer

kirza4 [7]

Answer:

8x8 Inc. is a provider of Voice over IP products. 8x8 products include cloud-based voice, contact center, video, mobile and unified communications for businesses.

Explanation:

7 0

2 years ago