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3 years ago

An object at 20∘c absorbs 25.0 j of heat. what is the change in entropy δs of the object?

2 answers:

5 0

From the definition of entropy, the entropy change of an object is
$\delta S = \frac{Q}{T}$
where
Q is the heat absorbed
T is the absolute temperature

in our problem, we have Q=25.0 J, while the absolute temperature is (converting in Kelvin)
$T=20 ^{\circ}C + 273 = 293 K$

and so the entropy change is
$\delta S= \frac{25.0 J}{293 K}=0.085 JK^{-1}$

cricket20 [7]3 years ago

5 0

ΔS of the object : <u>0.085324 J mol/K</u>

<h3>Further explanation </h3>

Entropy (with the symbol S) in thermodynamics indicated the degree of system disorder

Entropy like other thermodynamic terms can only be calculated from the initial and final changes

Entropy will also change in the process of changing energy forms

The value of ΔS ° can be calculated from standard entropy data

<h3>∆S ° (reaction) = ∑S ° (product) - ∑ S ° (reagent) </h3>

Entropy can also be calculated from the change in heat (ΔQ) to temperature (T), under Isothermal process (constant temperature) conditions

$\rm \boxed{\Delta S=\dfrac{\Delta Q}{T}}$

From this equation it can be seen that entropy will rise if the temperature gets lower (hot to cold)

An object at 20°C absorbs 25.0 j of heat

T = 20 + 273 = 293 K

ΔQ = 25 J

then:

Entropy: ΔS =

$\rm \Delta S=\dfrac{25\:J}{293\:K}=\boxed{\bold{0.08532\:J\frac{mol}{K}}}$

<h3>Learn more </h3>

Delta H solution

brainly.com/question/10600048

an exothermic reaction

brainly.com/question/1831525

as endothermic or exothermic

brainly.com/question/11419458

an exothermic dissolving process

brainly.com/question/10541336

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85.62 m

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s = Distance to Boralis orbit = 135 ly

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$L=\dfrac{L_0}{\gamma}\\\Rightarrow L=\dfrac{143}{1.67}\\\Rightarrow L=85.62\ m$

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Time taken from the perspective one Earth is 168.75 years

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3 years ago

A boy in a wheelchair (total mass 54.5 kg) has speed 1.40 m/s at the crest of a slope 2.10 m high and 12.4 m long. At the bottom

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Answer:

630.75 j

Explanation:

from the question we have the following

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work done (wd) = ?

we can calculate the work done by the boy in pushing the chair using the law of law of conservation of energy

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where wd = work done

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h = height

g = acceleration due to gravity

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wd = (0.5 x 54.5 x 6.9^2) - (0.5 x 54.5 x 1.4^2) + (41 x 12.4) - (54.5 X 9.8 X 2.1)

wd = 630.75 j

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