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Rus_ich [418]
3 years ago
8

How much heat in kj is released by burning 9.5 grams of methane?

Chemistry
1 answer:
tatyana61 [14]3 years ago
7 0
Methane is the compound CH4, and burning it uses the reaction:

CH4 + O2 -> CO2 + H2O, which is rather exothermic. To find the heat released by burning a certain amount of the substance, you should look at the bond enthalpy of each compound, and then compare the values before and after the reaction. In methane, there are 4 C-H bonds, which have bond energy of 416 kj/mol, resulting in a total bond energy of 1664 kj/mol. O2 is 494 kj/mol. Therefore we have a total of 2080 kj/mol on the left side. On the right side we have CO2, which has 2 C=O bonds, each at 799 kj/mol each, resulting in 1598 kj/mol, and H2O has 2 O-H bonds, at 459kj/mol each, resulting in a total of 2516 kj/mol on the right hand side. Now, this may be confusing because the left hand side seems to have less heat than the right, but you just need to remember: making minus breaking, which results in a total change of 436kj/mol heat evolved.

Now it is a simple matter of find the mols of CH4 reacted, using n=m/mr.

n = 9.5/16.042 = 0.592195 mol

Therefore, if we reacted 0.592195 mol, and we produced 436 kj for one mol, the total amount of energy evolved was 436*<span>0.592195 kj, or 258.197 kj.</span>
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PLEASE HELP!!!!!!!
Basile [38]

Answer:

2nd option

Explanation:

5 0
3 years ago
The boiling point of methanol is 64 7°C. Its melting point is -976°C. At room temperature (-25°C), methanol is in which state?
marissa [1.9K]

At -25 °C, methanol, whose boiling point is 64.7 °C and its melting point is -97.6 °C, is in the liquid state.

The melting point is the temperature at which a substance passes from solid to liquid. Below the melting point, a substance is in the solid state. Above the melting point, a substance is in the liquid or gas state.

The boiling point is the temperature at which a substance passes from liquid to gas. Below the boiling point, a substance is solid or liquid. Above the boiling point, a substance is in the gas state.

At -25 °C, methanol is above the melting point (-97.6 °C) and below the boiling point (64.7 °C). Thus, it is in the liquid state.

At -25 °C, methanol, whose boiling point is 64.7 °C and its melting point is -97.6 °C, is in the liquid state.

You can learn more about the melting and boiling points here: brainly.com/question/5753603?referrer=searchResults

3 0
2 years ago
Read 2 more answers
Consider the following intermediate chemical equations.
QveST [7]

Answer: 250 kJ

Explanation: According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to Hess’s law, the chemical equation can be treated as algebraic expressions and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

P_4(s)+6Cl_2\rightarrow 4PCl_3  \Delta H_1=-2439kJ (1)

4PCl_5(g)\rightarrow P_4(s)+10Cl_2(g)  \Delta H_2=3438kJ (2)

Net chemical equation:

PCl_5(g)\rightarrow PCl_3(g)+Cl_2(g)  \Delta H=? (3)

Adding 1 and 2 we get,

4PCl_5(g)\rightarrow 4PCl_3(g)+4Cl_2 \Delta H_3=\Delta H_1+\Delta H_2=-2439+3438=1000kJ   (4)

Now dividing equation (4) by 4, we get

PCl_5(g)\rightarrow PCl_3(g)+Cl_2

\Delta H=\frac{\Delta H_3}{4}=\frac{1000kJ}{4}=250kJ   (4)

8 0
2 years ago
Which of the following results in the release of nuclear energy?
Pepsi [2]

c.Both the breaking of nuclear bonds and the forming of nuclear bonds.

Explanation:

Nuclear energy is released by the breaking and forming of nuclear bonds. The breaking of nuclear bonds by unstable atoms is known as nuclear fission. The forming of nuclear bonds by combination of light atoms is known as nuclear fusion.

  • Nuclear fission is a radioactive decay process in which a heavy nucleus spontaneously disintegrates into lighter ones with the release of energy.
  • In nuclear fusion, atomic nuclei combines into larger ones with the release of large amount of energy.

Learn more:

Nuclear decay brainly.com/question/4207569

#learnwithBrainly

3 0
2 years ago
Convert 7.34 miles into meters (1mile = 1.6 Km)
Lera25 [3.4K]

Answer:

11812.58 meters = 11.81258 Km

Explanation:

hope that helps

8 0
3 years ago
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