Question

Question #f723a

Answer 1

Heat capacity of the sample `=1.44J//gm//"^oC`, rounded to second place in decimal.
Heat capacity of pure gold is known to be `=0.129J//gm//"^oC`
The value found in the experiment appears exceptionally high.

Explanation:

As the quantities have been given in CGS units, therefore, problem has been worked out in same units. Final answer posted in the asked units.

Value used

Specific heat of water`=1cal//gm=4.19kJ//kg`

Let the specific heat of the sample `=s_s`

Amount of heat exchanged is given as `DeltaQ=msDeltat`,
where `m` is the mass, `s` is the specific heat and `Deltat` is change in temperature.

Heat gained by `15.5gm` of water to change from at `24.4^oC` to water at `27.0^oC`,

`DeltaQ_(gai n ed)=msDeltat_w=15.5 times 1times (27.0-24.4)=40.3cal`

Simlarly heat lost by `2.58 g` of sample is given as
`DeltaQ_(lost)=ms_sDeltat_s=2.58xxs_sxx(72.3-27.0)=116.874s_s`

Since, `DeltaHeat_(lost)= Delta Heat_(gai n ed)`

`:. 116.874s_s=40.3`
`implies s_s=40.3/116.874`
or `s_s=0.34481cal//gm`
Changing to desired units. Recall `1 cal=4.184J`
Heat capacity of the sample`=1.44J//gm//"^oC`, rounded to second place in decimal.