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pychu [463]
4 years ago
5

Why do most sidewalks have cracks in them every few feet?

Chemistry
2 answers:
Licemer1 [7]4 years ago
8 0
This is actually a really good question! The lines are actually called "contraction joints." When the sidewalk is being made, the concrete used shrinks as it dries. This shrinking can cause cracks to form in the sidewalk, so to prevent the cracks from forming randomly, the builders make thin lines. Any cracks that form should follow the path of the line, since this is where the concrete is thinnest.

Hope this helps! :)
Elodia [21]4 years ago
7 0
It's because of the landscape, it changes over time.
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If you decreased the volume of a sample of gas by a factor of three while maintaining a constant pressure, how would the absolut
Rus_ich [418]
<h2>Answers to the whole assignment:</h2>

**Check for proof photos at the bottom.**

**Answers are in bold.**

__________________________________________________________

If you decreased the volume of a sample of gas by a factor of three while maintaining a constant pressure, how would the absolute temperature of the gas be affected?  

✔ it would decrease threefold

A gas at 300 K and 4.0 atm is moved to a new location with a temperature of 250 K. The volume changes from 5.5 L to 2.0 L. What is the pressure of the gas at the new location?  

✔ 9.2 atm

What is the partial pressure of 0.50 mol Ne gas combined with 1.20 mol Kr gas at a final pressure of 730 torr?  

✔ 215 torr

__________________________________________________________

How will the volume of a gas be affected if the pressure is tripled, but the temperature remains the same?  

✔ it is decreased to one third of its original volume

Why might a rubber raft burst if it is left in the sun on a summer day?  

✔ temperature increases, causing interior pressure to increase

__________________________________________________________

Complete the table by filling in the missing information.  

✔ pressure, volume    A  

✔ temperature, moles of gas   B  

✔ Charles’s law    C  

✔ V = kT    D  

✔ temperature, pressure   E  

✔ P = kT    F  

✔ number of moles only    G

__________________________________________________________

Match one graph shown at right to each of the gas laws named below.  

Charles’s law  

✔ d

Gay-Lussac’s law  

✔ b

Boyle’s law  

✔ e

__________________________________________________________

Left answers:  

1.31 atm A

0.44  atm B

Right answers:  

✔ decreases it    

✔ decreases it  

0.12  atm C

__________________________________________________________

<h2>Explanation:</h2>

When decreasing a volume while maintaining the same pressure, the temperature will have to decrease. When volume decreases, particles get squished, increasing pressure. But when temperature decreases, particles move slower, decreasing pressure. The lowered temperature decreases pressure, but the decreased volume increases pressure, so pressure is able to stay constant.

About the 3 main gas laws covered in Edge:

  • Charles's law says that under a constant pressure, when temperature increases, the volume increases, and vice versa. The equation for this law is V₁/T₁=V₂/T₂.
  • Gay-Lussac’s law says that under a constant volume, when temperature increases, the pressure increases, and vice versa. The equation for this law is P₁/T₁=P₂/T₂.
  • Boyle’s law says that under a constant temperature, when volume decreases, pressure increases, and vice versa. The equation for this law is P₁V₁=P₂V₂.

Note that P=pressure, V=volume, and T=temperature. When given a problem, plug in the given values into the correct spots and solve for the unknown value.

Here are photos of Edge. I hope this made your day a little easier.

5 0
3 years ago
Fundamental substances that cannot be broken down chemically into simpler subsances are______
Gemiola [76]

Answer:

A. Elements

Elements are substances that cannot be separated into simpler substances. Salt is made up of the elements sodium and chloride. Water is made up of the elements hydrogen and oxygen, to list a few.

7 0
3 years ago
TIMED ASSIGNMENT
galina1969 [7]

Answer:

27 grams

Explanation:

mass = density × volume

3 0
4 years ago
What does the constant bombardment of gas molecules against the inside walls of a container produce?
Bas_tet [7]
Pressure since pressure is defined as force per unit area and the molecules exert a force on the walls of the container when they bombard it
3 0
3 years ago
Why do you think knowing enthalpy of reaction might be useful?
mr Goodwill [35]
The Enthalpy of Reaction is the adjustment in the enthalpy of a compound response that happens at a consistent weight. It is a thermodynamic unit of estimation helpful for figuring the measure of vitality per mole either discharged or created in a response.
8 0
4 years ago
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