contestada

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2. 42 j/(g·k). Calculate q when 3. 65 kg of ethylene glycol is cooled from 132°c to 85°c.

Respuesta :

Taking into account the definition of calorimetry, the heat exchanged is -415,151 J.

In first place, calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).

In this way, between heat and temperature there is a direct proportional relationship.

The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat by the mass of the body.

So, the equation that allows to calculate heat exchanges is:

Q = c× m× ΔT

where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.

In this case, you know:

  • Q= ?
  • c= 2.42 [tex]\frac{J}{gK}[/tex]
  • m= 3.65 kg=3650 g (being 1 kg=1000 g)
  • ΔT= Tfinal - Tinitial= 85 C - 132 C= -47 C= -47 K being a temperature difference, it has the same value in °C and °K units

Replacing in the expression to calculate heat exchanges:

Q= 2.42 [tex]\frac{J}{gK}[/tex]× 3650 g× (-47 K)

Solving:

Q= -415,151 J

In this case, the value is negative because the heat is released.

In summary, the heat exchanged is -415,151 J.

Learn more:

  • brainly.com/question/11586486?referrer=searchResults
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