All categories

3 years ago

During cooling, the kinetic energy of the molecules falls. Why does this happen?

2 answers:

3 0

During cooling, the kinetic energy of the molecules falls, because, when cooling a substace, the particles (molecules) slow down.

The kinetic energy is related to the speed, such that the lower speed the lower kinetic energy.

Particles can translate and vibrate, in the case of gases and liquids, and only vibrate (in the case of solids).

As a substance is cooled the particles get closer and the motion (translation and vibration), slows down. You can see by the equation of the kinetic energy (KE):

KE = [1/2]mass×(speed)² that as the speed is lower the KE will also be lower.

Additionally, when the cooling does not drive a change of phase (gas to liquid, liquid to solid, or solid to gas), it drives a decrease on temperature. In this case you should know that the temperature is a measure of the kinetic energy: the lower the temperature, the lower the kinetic energy.

Elanso [62]3 years ago

3 0

Kinetic energy is the energy if an energy in motion. Molecules in a substance has varying kinetic energies because they move at different speeds. During cooling heat is released to the environment. Thus, when heat is being released, the kinetic energy of the molecules decreases.

You might be interested in

How is a line spectra created from a hot gas? a. photons are emitted when the amount of radioactive material in the gas decrease

fiasKO [112]

Answer:

c when electrons drop down from a high energy level they emit a photon.

Explanation:

4 0

1 year ago

List five household items that contain the same chemicals as cigarettes.

WITCHER [35]

Five household items that contain the same chemicals as cigarettes :-

Perfume
Household cleaning products
Beauty Products
Sunscreen
Water bottles

They contain toxic substances!

hope it helps!

5 0

3 years ago

Who is Alfred Wegener? What did he discover?

Aliun [14]

Answer:

Alfred Wegener proposed the theory of continental drift – the idea that Earth's continents move. Despite publishing a large body of compelling fossil and rock evidence for his theory between 1912 and 1929, it was rejected by most other scientists.

Hope this helps!

3 0

3 years ago

A plant extract can be obtained with organic solvents such as acetone or ethyl alcohol, and is composed of plant pigments such a

prohojiy [21]

Answer:

Here's what I get

Explanation:

A plant extract is a mixture because it contains different substances: acetone or ethanol, chlorophylls A and B, carotene and xanthophylls.

It is homogeneous because it is a solution. There is only one phase: the liquid phase. You cannot see the pigments as separate phases.

You can separate the pigments by paper, thin layer, or column chromatography.

Many schools use paper chromatography, because paper is cheap.

As the mixture of pigments follows the solvent up the paper, they separate into different coloured bands according to their attractive forces to the cellulose in the paper.

The chlorophylls are strongly attracted to the paper, so they don't travel very far.

The nonpolar carotene molecules have little attraction to the polar cellulose, so they are carried along by the solvent front.

8 0

3 years ago

Hello,

nikitadnepr [17]

Answer:

$a)\ 2FeSO4 \xrightarrow{\text{Heat}} SO_3+SO_2+Fe_2O_3\\b)\ Decomposition\ Reaction$

Explanation:

Ferrous Sulphate $(FeSO4)$ is generally found as Lime-Green Crystals. On heating, these crystals almost immediately turn white-yellow. They then, break down to produce an anhydrous mixture of Sulphur Trioxide $(SO_3)$ , Sulphur Dioxide $(SO_2)$ as well as Ferric Oxide $(Fe_2O_3)$ .

We can hence, frame a skeletal equation of this reaction and try to balance it.

Hence,

$FeSO4 \xrightarrow{\text{Heat}} SO_3+SO_2+Fe_2O_3$

Now,

a)In order to balance it through the 'Hit &Trial Method', we'll follow a series of steps:

1. First, lets compare the number of Fe (Iron) atoms on the RHS and LHS. We find that, the no. of Fe Atoms on the RHS is twice the number of Fe Atoms on the LHS. We hence, add a co-effecient 2 beside $FeSO_4$ .

2. Now, Iron atoms, Sulphur Atoms and Oxygen atoms occur 2, 2, 8 respectively on both the sides:

Hence, As all the other elements as well as iron, balance, we've arrived upon our Balanced Equation :

$2FeSO4 \xrightarrow{\text{Heat}} SO_3+SO_2+Fe_2O_3$

b) We know that, decomposition reactions are [generally] endothermic reactions in which Large Compounds decompose into smaller elements and compounds. Here, as Ferrous Sulphate decomposes into Sulphur Dioxide, Sulphur Trioxide and Ferric Oxide, the reaction that occurs here is Decomposition Reaction.

7 0

3 years ago