What temperature scale do weather reporters in the United states use to tell you how hot it is outside?

For each process, predict the sign on the entropy change and write a sentence or two to explain how to make this prediction with

MrRa [10]

Answer: a. A solid melts: $\Delta S=+ve$

b. a vapor is converted to solid: $\Delta S=-ve$

c. a liquid freezes: $\Delta S=-ve$

d. A solid sublimes: $\Delta S=+ve$

e. a vapor condenses to liquid : $\Delta S=-ve$

f. a liquid boils: $\Delta S=+ve$

g. dissolving a tablespoon of salt in water: $\Delta S=+ve$

h. combustion of gasoline: $\Delta S=+ve$

Explanation:

Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy change is negative and vice versa.

a. A solid melts: The solid is converting to liquid, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change $(\Delta S)$ is positive.

b. a vapor is converted to solid: The gas is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger Thus the entropy change $(\Delta S)$ is negative.

c. a liquid freezes: The liquid is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change $(\Delta S)$ is negative.

d. A solid sublimes: The solid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change $(\Delta S)$ is positive.

e. a vapor condenses to liquid : The gas is converting to liquid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change $(\Delta S)$ is negative.

f. a liquid boils: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change $(\Delta S)$ is positive.

g. dissolving a tablespoon of salt in water: The solid is converting to ions , thus the randomness is increasing as the ions can move freely. Thus the entropy change $(\Delta S)$ is positive.

h. combustion of gasoline: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change $(\Delta S)$ is positive.

6 0

2 years ago

Which unit is used for measuring atomic mass?

Kryger [21]

An atomic mass unit is a unit of measurement that is used to measure the mass of atoms. The atomic mass unit (abbreviated: amu or u) is roughly equal to the mass of 1 proton<span> or 1 neutron. The unified atomic mass unit and the dalton are different names for the same thing. The dalton name is used more over time.</span>

6 0

3 years ago

Read 2 more answers

Pls help!!!!!

erica [24]

Answer:

moving i think! Hope this helps

Explanation:

3 0

3 years ago

Read 2 more answers

What happens on a molecular level when a diatomic molecule is a gas but is then cooled to a solid?

irina1246 [14]

Answer:

As an example of the processes depicted in this figure, consider a sample of water. When gaseous water is cooled sufficiently, the attractions between H2O molecules will be capable of holding them together when they come into contact with each other; the gas condenses, forming liquid H2O. For example, liquid water forms on the outside of a cold glass as the water vapor in the air is cooled by the cold glass.

Explanation:

Hopefully that helps!

4 0

3 years ago

The law of conservation of mass states that mass is neither created nor destroyed during a chemical reaction. This can be gleane

GenaCL600 [577]

Answer : The total mass of oxygen gas released in the reaction will be, 12.8 grams

Explanation :

Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.

This also means that total mass on the reactant side must be equal to the total mass on the product side.

The balanced chemical reaction will be,

$2MgO\rightarrow 2Mg+O_2$