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bixtya [17]
3 years ago
15

Use Hess's Law to calculate the enthalpy change for the reaction

Chemistry
1 answer:
Marysya12 [62]3 years ago
3 0

Answer:

ΔH = 125.94kJ

Explanation:

It is possible to make algebraic sum of reactions to obtain ΔH of reactions (Hess's law). In the problem:

1. 2W(s) + 3O2(g) → 2WO3(s) ΔH = -1685.4 kJ

2. 2H2(g) + O2(g) → 2H2O(g) ΔH = -477.84 kJ

-1/2 (1):

WO3(s) → W(s) + 3/2O2(g) ΔH = 842.7kJ

3/2 (2):

3H2(g) + 3/2O2(g) → 3H2O(g) ΔH = -716.76kJ

The sum of  last both reactions:

WO3(s) + 3H2(g) → W(s) + 3H2O(g)

ΔH = 842.7kJ -716.76kJ

<h3>ΔH = 125.94kJ </h3>
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<h3>How do the intermolecular forces affect physical properties?</h3>

The forces that bind two molecules together are known as intermolecular forces. Intermolecular forces have an impact on physical properties. Strong and weak forces both exist; the stronger the force, the more energy is needed to separate the molecules from one another. As intermolecular forces increase melting, boiling, and freezing points rise.

The following intermolecular forces are listed in order of strength:

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1 year ago
Why do you think forensic scientists are so careful that the tests they do are sensitive, reproducible, and specific?
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4 0
3 years ago
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What is the density at 20 degrees Celsius of 12.0 mL of a liquid that has a mass of 4.05g?​
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Answer:

<h3>The answer is 0.34 g/mL</h3>

Explanation:

The density of a substance can be found by using the formula

density =  \frac{mass}{volume}  \\

From the question we have

density =  \frac{4.05}{12}  \\  = 0.3375

We have the final answer as

<h3>0.34 g/mL</h3>

Hope this helps you

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