Question

HELP!

In an experiment, equal amounts of water and sand were heated under a lamp. The initial and final temperatures of each were recorded. A partial record of the temperature is shown.
Experimental Record Substance Initial Temperature Final Temperature
Water 20 °C ?
Sand 20 °C 26 °C
Which statement about the final temperature of water is correct?

It will be less than 26 °C as sand has a relatively higher specific heat than water.

It will be less than 26 °C as water has a relatively higher specific heat than sand.

It will be more than 26 °C as sand needs relatively higher energy than water to raise its temperature.

It will be more than 26 °C as water needs relatively higher energy than sand to raise its temperature.

Answer 1

It will be the second answer

Explanation: This is because water has a specific heat and needs more energy to heat than sand does.

Answer 2

• It will be less than 26 °C as water has a relatively higher specific heat than sand.

Step-by-step explanation:

The specific heat of a substance is the amount of heat energy absorbed by one unit of mass of the substance when its temperature increases one unit.

From that, you can derive the equation for the specific heat of a substance:

• specific heat = heat / (mass × ΔT)

Thus, assuming that all the heat provided by the lamp to both samples is the same and, as given, the amount (mass) of both samples is also the same, you have that the specific heat of the samples will be:

• specific heat = constant / ΔT

So, specific heat and ΔT are inversely related.

It is known that water has a higher specific heat than sand (that is why the sand on the shore of a beach is, during the day, hotter than the water and your feet get burned when you walk on a sandy beach on a sunny day).

Then, since the specific heat of water is greater than the specific heat of sand, the increase of temperature of water will be lower and, consequently, water will reach a lower final temperature than sand, when equal amounts of water and sand are heated as described in the experiment. This is the second choice: the final temperature of water is less than 26°C as water has a relatively higher specific heat than water.