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3 years ago

Explain the changes that take place at the molecular level when a substance is superheated or supercooled ?

1 answer:

4 0

Only gas or vapor can be superheated. Use water as an example. Water at sea level boils at 212 degrees F. When heated to 212 degrees F, the molecules that make up water are moving at a high enough speed that they overcome the air pressure above the water. And for supercooled only liquids or solids can be supercooled for example Liquid water at sea level has a saturation (boiling) temperature of 212 degrees F. If we were to add heat to the saturated water, it would first boil away with no change in temperature (remember latent heat?) and then become superheated if still more heat were added to the vapor (steam) after it had all turned to a vapor.

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When you heat a substance what happens to the molecules

tatyana61 [14]

I'm pretty sure they come closer, and on the small chance i'm wrong, they separate.<span />

6 0

2 years ago

Read 2 more answers

A sample weighing 3.110 g is a mixture of Fe 2 O 3 (molar mass = 159.69 g/mol) and Al 2 O 3 (molar mass = 101.96 g/mol). When he

grandymaker [24]

Answer:

The mass fraction of ferric oxide in the original sample : $\frac{723}{3110}$

Explanation:

Mass of the mixture = 3.110 g

Mass of $Fe_2O_3=x$

Mass of $Al_2O_3=y$

After heating the mixture it allowed to react with hydrogen gas in which all the ferric oxide reacted to form metallic iron and water vapors where as aluminum oxide did not react.

$Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(g)$

Mass of mixture left after all the ferric oxide has reacted = 2.387 g

Mass of mixture left after all the ferric oxide has reacted = y

$x=3.110 g- y=3.110 g - 2.387 g = 0.723 g$

The mass fraction of ferric oxide in the original sample :

$\frac{0.723 g}{3.110 g}=\frac{723}{3110}$

5 0

3 years ago

a substance that undergoes a physical change like melting is still the same substance is it true or false

Juli2301 [7.4K]

the answer would be true

3 0

3 years ago

Read 2 more answers

I have 345mL of a 1.5M NaCl solution. If I boil the water until the volume of the solution is 250mL, what will the molarity of t

Karo-lina-s [1.5K]

Answer is
C. 2.07 M

For explanation

M1V1 = M2V2

M2 = (M1V1)/V2

M2 = (1.5M x 345ml) / 250 ml

:. M2 = 2.07 M

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3 years ago

What is the relationship between a scientific theory and a scientific law

grigory [225]

A scientific theory focuses on explaining a phenomenon, while a law will have a generalised statement about said phenomenon. Often times, we use laws to help us develop theories. =)

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3 years ago