Question

500cm3 of water is to be jeated from room temperature 28oc to 100oc in order to prepare ahot cup pf coffee. What os the minimum heat required

Answer 1

The minimum heat required is 171626 joules.

Step-by-step explanation:

By First Law of Thermodynamics, the amount of heat (
`Q`), in joules, is equal to the change in internal energy of water. The minimum heat required is the sensible heat necessary to heat up the water. That is:

`Q = \rho\cdot V \cdot c\cdot \Delta T` (1)

Where:

`\rho` - Density of water, in kilograms per cubic meter.

`V` - Volume of water, in cubic meters.

`c` - Specific heat of water, in joules per kilogram-degree Celsius.

`\Delta T` - Change in temperature, in degrees Celsius.

If we know that
`\rho = 1000\,(kg)/(m^(3))`,
`V = 5* 10^(-4)\,m^(3)`,
`c = 4186\,(J)/(kg\cdot ^(\circ)C)` and
`\Delta T = 82\,^(\circ)C`, then the minimum heat required is:

`Q = 171626\,J`

The minimum heat required is 171626 joules.