Calculating Specific Heat: 50g of Unknown Substance at 25°C to 89.7°C

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SUMMARY

The discussion centers on calculating the specific heat of an unknown substance using the formula q = mcΔT. A 50-gram sample absorbed 2.578 kJ of energy while its temperature increased from 25°C to 89.7°C. The correct approach involves converting the energy from kilojoules to joules (2.578 kJ = 2578 J) and applying the formula with ΔT calculated as 64.7°C. The final calculation for specific heat is c = q / (mΔT), leading to a definitive value for the specific heat in J/g°C.

PREREQUISITES
  • Understanding of the specific heat formula q = mcΔT
  • Knowledge of unit conversions, specifically kJ to J
  • Basic concepts of thermodynamics and heat transfer
  • Familiarity with temperature scales (Celsius)
NEXT STEPS
  • Practice calculating specific heat with different substances and energy values
  • Explore the concept of calorimetry and its applications
  • Learn about the specific heat capacities of common materials
  • Investigate the relationship between specific heat and phase changes
USEFUL FOR

Students in chemistry or physics, educators teaching thermodynamics, and anyone interested in understanding heat transfer and specific heat calculations.

Jurrasic
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50 grams of a substance absorbed 2.578 kj of energy as it changed from 25 degrees celsius to 89.7
What is the specific heat of the unknown substance in J/gC ?

Is it correct to use :
q = m c delta T

q = specific heat
m = mass
c = ?
delta T here is 64.7

The answer seems really big? Is it :
(50grams) x (2578kj) x (64.7 C ) = answer ?
That seems wrong? Is there a more correct way to do it?
 
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You've got your quantities confused. q = heat put into or taken away from the substance in Joules. c = specific heat of the substance in J/gC.
 
SteamKing said:
You've got your quantities confused. q = heat put into or taken away from the substance in Joules. c = specific heat of the substance in J/gC.

LOL oh thanks :)~

Got it working now haha
 

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