Question

The specific heat of ethanol is 2.46 J/g C. how many joules of heat are required to heat 193g ethanol from 19.00C to 36.00C?

Answer 1

Hint: The specific heat capacity of a substance is defined as the amount of heat required to raise the temperature of one kilogram of the substance by 1 Celsius to 1 Kelvin. In other words, it is the amount of heat energy required to one unit mass of a substance to raise its temperature by one unit.

Complete answer:
- The specific heat of a sample of a substance divided by the mass of the same sample. Basically, it is the amount of energy that should be added to one unit of mass of the substance in order to cause an increase of one unit in its temperature in the form of heat.
- The specific heat of substance sometimes changes, often substantially, depending on the starting temperature of the sample and pressure is applied. Thus, it should be considered to be a function of these two variables.
- The mathematical representation of specific heat of any substance can be written as
$Q$ = $mC\Delta T$
Where, $Q$ = required heat energy
$m$ = mass of the substance whose temperature needs to be raised
$C$ = specific heat of a substance
$\Delta T$ = change in temperature
- Now, using the equation mentioned above, we will put the values given in question.
$Q = 193 \times 2.46 \times (36.0 – 19.0)$
$Q = 8.070 kJ$

Note:
The specific heat generally varies with temperature and is different for each state of matter. The specific heat of gas may be significantly higher when it is allowed to expand as it is heated at constant pressure.