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4 years ago

What is the internal energy of 7.00 mol of n2 gas at 40c?

Physics

1 answer:

emmasim [6.3K]4 years ago

4 0

To find the internal energy of gas we can use

$U = \frac{f}{2}nRT$

here given that

Number of moles (n) = 7 moles

Temperature T = 40 + 273 = 313 K

degree of freedom(f) = 5 (for diatomic gas)

now by above formula

$U = \frac{5}{2}* 7 * 8.31 * 313$

$U = 45518.03 J$

<em>So it is approximately 45500 J (option C)</em>

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Answer:

Explanation:

Given

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$n_1=\frac{P_1V_1}{RT_1}$

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when some gas escape out

no of moles is equal to

$n_2=\frac{P_2\times V_2}{R\cdot T_2}$

$n_2=\frac{1.01\times 10^5\times 60}{R\cdot 302}$

remaining no of moles $=n_1-n_2$

$=\frac{1.01\times 10^5\times 60}{R\cdot 289}-\frac{1.01\times 10^5\times 60}{R\cdot 302}$

$=\frac{1.01\times 10^5\times 60}{R}(\frac{1}{289}-\frac{1}{302})$

Mass of air escape out

$=(n_1-n_2)\times M$

$=(\frac{1.01\times 10^5\times 60}{R}(\frac{1}{289}-\frac{1}{302}))\times 28$

$=25.272\times 10^3\ g$

$m=25.272\ kg$

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4 years ago

A spring has a natural length of 14 cm. If a 23-N force is required to keep it stretched to a length of 20 cm, how much work W i

lubasha [3.4K]

Answer:

1.78 J

Explanation:

Find the spring coefficient using Hooke's law:

F = k Δx

23 N = k (0.20 m − 0.14 m)

k = 383.33 N/m

The work is the change in energy:

W = PE₂ − PE₁

W = ½ kx₂² − ½ kx₁²

W = ½ k (x₂² − x₁²)

W = ½ (383.33 N/m) ((0.17 m)² − (0.14 m)²)

W = 1.78 J

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3 years ago

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Answer:

A. Elements with intermediate numbers of valence electrons are the last chemically stable.

Explanation:

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