An object with a mass of 18 g18g is dropped into 400 mL400mL of water at 0^@C0∘C. If the object cools by 150 ^@C150∘C and the water warms by 12 ^@C12∘C, what is the specific heat of the material that the object is made of?
1 Answer
Dec 28, 2017
Explanation:
- Given the volume of water used as medium to cool down the object, its mass can be derived through the density formula; that is,
rho=m/Vρ=mV
m=rhoxxVm=ρ×V
m=(1g)/cancel((ml))xx400cancel(ml)
m=400gH_2O - Find the heat absorbed (gained) by the water that increases its temperature by
12^o . Knowing theCp_w=(4.18J)/(g*C) , heat gained can be calculated by:
Q=mCpDeltaT
Q=(400cancel(g))((4.18J)/cancel((g*C)))(12)cancel(^oC)
Q=20,064J=20.064kJ - Since heat lost=heat gained; therefore, the
Cp of the material can be computed as;
Q=mCpDeltaT
Cp_(o)=(Q)/(mDeltaT)
Cp_(o)=(20,064J)/((18g)(150^oC))
Cp_(o)=(7.4311J)/(g*C)