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kakasveta [241]
3 years ago
5

Use the formation reactions below such that when added together, they match the balanced equation for the combustion of methane.

Chemistry
1 answer:
muminat3 years ago
7 0

Answer:

ΔH of the reaction is -802.3kJ.

Explanation:

Using Hess's law, you can know ΔH of reaction by the sum of ΔH's of half-reactions.

Using the reactions:

<em>(1) </em>Cgraphite(s)+ 2H₂(g) → CH₄(g) ΔH₁ = −74.80kJ

<em>(2) </em>Cgraphite(s)+ O₂(g) → CO₂(g) ΔH₂ = −393.5k J

<em>(3) </em>H₂(g) + 1/2 O₂(g) → H₂O(g) ΔH₃ = −241.80kJ

The sum of (2) - (1) produce:

CH₄(g) + O₂(g) → CO₂(g) + 2H₂(g) ΔH' = -393.5kJ - (-74.80kJ) = -318.7kJ

And the sum of this reaction with 2×(3) produce:

CH₄(g) + 2 O₂(g) → CO₂(g) + 2H₂O(g) And ΔH = -318.7kJ + 2×(-241.80kJ) =

<em>-802.3kJ</em>

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Karolina [17]

Answer:

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Explanation:

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2 years ago
In a chemical formula such as C6H12O6 and H2O, what do you call the little numbers below the normal line of text.
Morgarella [4.7K]

These are called subscript number.

That is the number below the normal line of test are called subscript number.

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3 years ago
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An acidic fog in pasadena was found to have a ph of 2.50. which expression represents this ph measurement?
joja [24]

Supposing a temperature of 25 degrees and supposing that all activity coefficients are 1 

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5 0
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The chart shows the solubility of different substances.
Annette [7]
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Explanation:

The chart is missing so there is no way to tell what does the graph show.

Yet, I can help you because I can explain the status of each statement of the choices. As you will see there is only one possibility..

<span>1) Temperature can change the solubility of a solute.

Yes, temperature definetly can, and mostly do, modify the solubility of a solute.

You can search any chart of solubility and will find that.

I can give you two examples:

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b) Carbon dioxide gas: the soft drinks have CO₂ molecules dissolved in it.
 
The higher the temperature of the soft drink the less the amount of CO₂(g) that can be dissolved. That is why the soda bottling plants cool the beverage before adding the CO₂(g).

2) </span><span>Temperature has no affect on the solubility of a solute.

Since this is the opposite to the first statement and the first is true, this is false.

3) Salt has a greater solubility than sugar.

False.

This is an empirical result, which you cannot predict theoretically. So you need to see at the data either in a table or in a chart. Else you can test it at home. After the empirical data are shown it results that more grams of sugar can be dissolved in water compared to salt.

That is something you ca see in a chart or you can prove by yourself.

4) Nitrite salt has a greater solubility than sugar. </span>

False.

Looking at some data you can find that sodium nitrite solutiliby is aroun  70 - 100 g/10 g while sugar (sucrose) solutiblity is around 180 - 235 g/ 100 g.

8 0
3 years ago
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