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nexus9112 [7]
3 years ago
7

Assume that the density and heat of combustion of E85 can be obtained by using 85 % of the values for ethanol and 15 % of the va

lues for gasoline. How much energy could be released by the combustion of 3.5 L of E85?
Chemistry
1 answer:
Alika [10]3 years ago
8 0

Answer:

87.4 J

Explanation:

The density of the gasoline is 0.70 g/mL, and the density of the ethanol is 0.79 g/mL. The heat combustions (the heat released in a combustion reaction) are 5,400 kJ/mol for gasoline, and 1,370 kJ/mol for ethanol.

For 3.5 L of E85, the volumes of gasoline and ethanol are:

Vgasoline = 0.15 * 3.5 = 0.525 L = 5.25x10⁻⁴ mL

Vethanol= 0.85 * 3.5 = 2.975 L = 2.975x10⁻³ mL

The mass of gasoline and ethanol presented in that sample of E85 is the volume multiplied by the density:

mgasoline = 5.25x10⁻⁴ * 0.70 = 3.675x10⁻⁴ g

methanol = 2.975x10⁻³ * 0.79 = 2.35025x10⁻³ g

The number of moles for each substance is it mass divided by its molar mass. The molar masses are 114 g/mol for gasoline, and 46 g/mol for ethanol:

ngasoline = 3.675x10⁻⁴/114 = 3.224x10⁻⁶ mol

nethanol = 2.35025x10⁻³ /46 = 5.109x10⁻⁵ mol

The energy released is the heat combustion multiplied by the number of moles, so:

Egasoline = 5,400 * 3.224x10⁻⁶ = 0.0174 kJ = 17.4 J

Eethanol = 1,370 * 5.109x10⁻⁵ = 0.07 kJ = 70 J

So, the energy released by the E85 is the sum of the energy released by ethanol and gasoline:

The energy released by E85 = 87.4 J

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Answer:

Explanation:

Every atom has no overall charge (neutral). This is because they contain equal numbers of positive protons and negative electrons. These opposite charges cancel each other out making the atom neutral.

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2 years ago
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11Alexandr11 [23.1K]

Answer:

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7 0
3 years ago
Read 2 more answers
Which element would be expected to have a similar physical and chemical properties as oxygen, and why?
soldi70 [24.7K]

Oxygen and Sulfur are in the same group.

Sulfur is the next element in the group, and it reacts with hydrogen gas (H2) in a manner similar to oxygen.

5 0
3 years ago
A rule of thumb in baking is that 1/2 teaspoon of baking soda is neutralized by one cup of sour milk. the acid component in sour
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Answer : The ionic equation will be:

CH_3CH(OH)COO^-(aq)+H^+(aq)+Na^+(aq)+HCO_3^-(aq)\rightarrow CH_3CH(OH)COO^-(aq)+Na^+(aq)+H_2O(l)+CO_2(g)

Explanation :

Neutralization reaction : It is a type of chemical reaction in which an acid react with a base to give salt and water as a product that means it reacts to give a neutral solution.

When baking soda (sodium hydrogen carbonate) base react with lactic acid then it react to gives sodium lactate, carbon dioxide and water as a product.

The balanced chemical reaction will be:

CH_3CH(OH)COOH(aq)+NaHCO_3(aq)\rightarrow CH_3CH(OH)COONa(aq)+H_2O(l)+CO_2(g)

The ionic equation will be:

CH_3CH(OH)COO^-(aq)+H^+(aq)+Na^+(aq)+HCO_3^-(aq)\rightarrow CH_3CH(OH)COO^-(aq)+Na^+(aq)+H_2O(l)+CO_2(g)

3 0
3 years ago
To plot the calibration curve, you need to prepare iron solutions with known concentrations and measure their absorbance.
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To plot the calibration curve, you need to prepare iron solutions with known concentrations and measure their absorbance. You need to pipet 0 mL of the diluted solution to have 0.00 mg of iron.

In spectrophotometry, to plot the calibration curve, you need to prepare solutions with known concentrations and measure their absorbance.

We have a standard iron solution with a concentration of 0.2500g/L of pure iron (C₁). We pipet 25.00mL (V₁) of this standard iron solution into a 500mL (V₂) volumetric flask and dilute up to the mark with distilled water.

We can calculate the concentration of the diluted solution (C₂) using the dilution rule.

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Then, if we wanted to prepare the blank, that is, the solution that contains the same matrix but not the analyte, and whose concentration in iron is 0.00 mg/L, we wouldn't pipet any of the diluted solution.

To plot the calibration curve, you need to prepare iron solutions with known concentrations and measure their absorbance. You need to pipet 0 mL of the diluted solution to have 0.00 mg of iron.

Learn  more: brainly.com/question/24195565

8 0
2 years ago
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