Question

You are given an unknown solid substance of mass 500 g and you want to estimate its specific heat. unfortunately, you don’t have a thermometer handy. instead, you throw the substance into a bucket of boiling water and wait until its in equilibrium with the boiling water. you then remove the hot substance from the boiling water and put it into a beaker with 400 ml ethyl alcohol at room temperature. immediately after adding the hot substance into the beaker, the volume scale reads 430 ml. after a while, when the alcohol and the substance reach equilibrium, the volume scale reads 429 ml.
What is the specific heat of the substance?
Hint: Assume that no heat was neither lost during the transfer nor to the environment. You can neglect the mass of the beaker. Room temperature is approximately 20 deg C and the density of ethyl alcohol is 789 kg/m^3.

A) 385 J/(mol K)
B) 4,057 J/mol K)
C) 2,090 J/(mol K)
D) 449 J/(mol K)
E) 7,500 J/(mol K)

Answer 1

Answer:

Option C) 2,090 J/(mol K)

Explanation:

Data:

Volume in the beaker = 429 ml

temperature  = 20° C

Density = 789 kg/m³

Equilibrium reading = 429

volume change = 29 ml

                          = 0.029 L

Energy change = mcΔT

                       U + PΔV