Question

Specific heat of a substance can be:
A) Zero
B) Positive
C) Infinity
D) Negative

Answer 1

Hint: Specific heat is defined as the quantity of heat per unit area of mass which is required to raise the temperature by one degree Celsius.SI unit of specific heat is joule per kilogram per kelvin ($Jk{{g}^{-1}}{{K}^{-1}}$ ) and C is used to denote specific heat .Different substances will have different specific heat (C ).

Complete answer:
Specific heat of a substance will depend on its nature. As the temperature varies the specific heat capacity also varies and it’s different for solid, liquid and gaseous states. In the process of melting the specific heat capacity is infinity.
Specific heat capacity of substance is a scalar quantity. Which has only magnitude and there is no direction. And specific heat capacity does not depend upon the size of the sample.
The dimensional formula of specific heat is $[{{L}^{2}}{{T}^{-2}}{{K}^{-1}}]$
The specific heat of a substance is given by:
\[C=\dfrac{dQ}{\partial T\partial m}kJ{{K}^{-1}}k{{g}^{-1}}\]
Where $\partial T$ = change in temperature
$dQ$ =heat exchange
$\partial m$ =change in mass
There is no change in temperature for an isothermal process
So $\partial T$ =0
which in turn implies that C=$\infty $
In an adiabatic process heat exchange will not take place
so $dQ$ =0
Which in turn implies that C=0
Specific heat is negative when heat is observed by the system or else by the substance.
So the specific heat of the substance is negative

The correct option is D .

Note:
Students specific heat capacity of water is $2.09J{{g}^{-1}}{}^{0}C$ and compared to other substance water has a little bit more specific heat , sand has less specific heat and conductors are good conductors of heat and electricity . Insulators are bad conductors of heat and electricity. Specific heat will not be applicable in case of phase change.