Problem: To determine whether a shiny gold-colored rock is actually gold, a chemistry student decides to measure its heat capacity. She first weighs the rock and finds it has a mass of 4.0 g. She then finds that upon absorption of 54.6 J of heat, the temperature of the rock rises from 25 oC to 56 oC. Find the specific heat capacity of the substance composing the rock and determine whether the value is consistent with the rock being pure gold.SubstanceSpecific heatcapacity, Cs (J/(g oC))*ElementsLead0.128Gold0.128Silver0.235Copper0.385Iron0.449Aluminum0.903CompoundsEthanol2.42Water4.18MaterialsGlass (Pyrex)0.75Granite0.79Sand0.84* At 298 K.

FREE Expert Solution

Q=mcT

Q = 54.6 J

m = 4.0 g

ΔT = 56°C - 25°C = 31°C

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Problem Details

To determine whether a shiny gold-colored rock is actually gold, a chemistry student decides to measure its heat capacity. She first weighs the rock and finds it has a mass of 4.0 g. She then finds that upon absorption of 54.6 J of heat, the temperature of the rock rises from 25 oC to 56 oC

Find the specific heat capacity of the substance composing the rock and determine whether the value is consistent with the rock being pure gold.


SubstanceSpecific heat
capacity, Cs 
(J/(g oC))*
Elements
Lead0.128
Gold0.128
Silver0.235
Copper0.385
Iron0.449
Aluminum0.903
Compounds
Ethanol2.42
Water4.18
Materials
Glass (Pyrex)0.75
Granite0.79
Sand0.84
* At 298 K.


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