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Maru [420]
3 years ago
10

Please help it’s due today I will give brainliest

Chemistry
1 answer:
Thepotemich [5.8K]3 years ago
7 0

1st and 4th options are suitable answers, as these 2 changes are not exactly physical changes as it cant return back to original form and as well as its not cooling, so I feel its 1st and 4th options

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In the following reaction, what is the quantity of heat (in kJ) released when 5.87 moles of CH₄ are burned?
IRISSAK [1]

Taking into account the definition of enthalpy of a chemical reaction, the quantity of heat released when 5.87 moles of CH₄ are burned is 4,707.74 kJ.

The enthalpy of a chemical reaction as the heat absorbed or released in a chemical reaction when it occurs at constant pressure. That is, the heat of reaction is the energy that is released or absorbed when chemicals are transformed into a chemical reaction.

The enthalpy is an extensive property, that is, it depends on the amount of matter present.

In this case, the balanced reaction is:

CH₄ (g) + 2 O₂ (g) → CO₂ (g) + 2 H₂O(g)

and the enthalpy reaction ∆H° has a value of -802 kJ/mol.

This equation indicates that when 1 mole of CH₄ reacts with 2 moles of O2, 802 kJ of heat is released.

When 5.87 moles of CH₄ are burned, then you can apply the following rule of three: if 1 mole of CH₄ releases 802 kJ of heat, 5.87 moles of CH₄ releases how much heat?

heat=\frac{5.87 molesof CH_{4}x802 kJ}{1 mol of CH_{4} }

<u><em>heat= 4,707.74 kJ</em></u>

Finally, the quantity of heat released when 5.87 moles of CH₄ are burned is 4,707.74 kJ.

Learn more:

  • brainly.com/question/15355361?referrer=searchResults
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5 0
2 years ago
19. Which of the following best describes the role of the spark from the spark plug in an automobile engine?
sergey [27]

The role of a spark plug is to supply some of the energy of activation for the combustion reaction.

<u>Explanation:</u>

  • A Spark plug is a tiny bolt of lightning in which a spark of electricity is emitted across a gap creating the ignition of the combustion chamber thereby starting the engine. By putting an engine piston in motion we can power up which produces a smooth burn of the compressed air-fuel mixture.
  • An electrical device that fits into the cylinder head and ignites compressed aerosol gasoline by an electric spark. They have an insulated electrode connected to a coil that ignites thereby producing sparks.
  • The spark plug works as a heat exchanger. They tend to pull unwanted thermal energy from the combustion chamber and heat is transferred to the engine's cooling system. Thus they supply some of the energy for the activation of engines.
4 0
3 years ago
How many grams of C3H8 are in a 7 L tank at 293 K and 5.45 atm?
Sophie [7]
1.59 moles















































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8 0
3 years ago
Which of these is a reason why nuclear power is important?
OlgaM077 [116]

Answer:

C Fossil fuels will run out soon

5 0
2 years ago
Read 2 more answers
Can someone help on this?
AlexFokin [52]

Answer:

Igneous=B

Sedimentary=C

Metamorphic=A

Weathering is when=B

If sedimentary rock.....=C

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