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3 years ago

How can we use rocks to determine how an area used to look in the past?

1 answer:

tatiyna3 years ago

8 0

We can use rocks to determine if the animals from to day have changed from the past.
Rocks also help us know if rivers once flowed through an area.
We use them to find out what type of animals live then that are extinct now.

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a sample of gas initially occupies 5.50 liter at a pressure of 0.750 atm at 13.0 C. what will the temperture change to 22.5 C an

sergey [27]

Answer:

The pressure will be 2.84 atm

Explanation:

The gas laws are a set of chemical and physical laws that allow us to determine the behavior of gases in a closed system. The parameters evaluated in these laws are pressure, volume, temperature and moles.

Boyle's law indicates that the volume is inversely proportional to the pressure: if the pressure increases, the volume decreases and if the pressure decreases, the volume increases. Boyle's law is expressed mathematically as:

P * V = k

On the other hand, Charles's law indicates that with increasing temperature, the volume of the gas increases and with decreasing temperature, the volume of the gas decreases. That is, they are directly proportional. This is expressed mathematically as:

$\frac{V}{T} =k$

Finally, the Gay-Lussac law says that at constant volume, the pressure of the gas is directly proportional to its temperature. Mathematically, it is expressed as:

$\frac{P}{T} =k$

Combined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law:

$\frac{P*V}{T}=k$

When you want to study two different states, an initial and a final one of a gas, you can use the following expression:

$\frac{P1*V1}{T1}=\frac{P2*V2}{T2}$

In this case:

P1= 0.750 atm
V1= 5.50 L
T1= 13 C= 286 K (being 0 C=273 K)
P2=?
V2= 1.50 L
T2= 22.5 C=295.5 K

Replacing:

$\frac{0.750 atm*5.50 L}{286 K}= \frac{P2*1.50 L}{295.5 K}$

Solving:

$P2=\frac{295.5K}{1.50L} *\frac{0.750 atm*5.50 L}{286 K}$

P2= 2.84 atm

The pressure will be 2.84 atm

8 0

4 years ago

There are several aromatic compounds with the formula C8H9Cl. Draw those that have a trisubstituted ring where the methyl groups

Kryger [21]

Answer:

$3-Chloro-1,2-dimethylbenzene$

$4-Chloro-1,2-dimethylbenzene$

Explanation:

Such types of compounds in which conjugated planer ring system and delocalized pi electrons are present are called aromatic compounds such as Toluene, Benzene and some other. Generally, these compounds follow Huckle's rule. The trisubstituted ring means a compound in which three hydrogen atoms are replaced by three other groups. In the given compound two hydrogen atoms are replaced by two methyl groups and one hydrogen atom is replaced by one Chlorine atom. From the given compound $3-Chloro-1,2-dimethylbenzene$ , and $4-Chloro-1,2-dimethylbenzene$ can be drawn.

7 0

4 years ago

Over a period of 30 days a student studied the night sky and recorded his observations. One night he watched a shooting star str

Temka [501]

Answer:

meteor

Explanation:

The most logical identification of a "shooting star" is a meteor. A meteor is basically any material from outerspace that falls to Earth. The main characteristic of a meteor is that from our point of view on the surface of the Earth it looks like a shooting star because we see a streak of light behind it. This light is simply dust and rock from the meteor burning up as it enters the Earth's atmosphere, leaving a "tail" of light behind it. Which to us looks like a shooting star.

8 0

3 years ago

What isa the UIPAC name H3C CH2-CH2-CH3 CH-CH-CH2-CH3 H3C—CH CH CH3

aliina [53]

Answer:

4–ethyl–2,3–dimethylheptane

Explanation:

To name the compound given above, do the following:

1. Locate the longest continuous carbon chain. This gives the parent name of the compound. In this case, the longest continuous carbon chain is 7. Thus the parent name is Heptane.

2. Identify the substituent group attached to the compound. In this case, the substituent group attached are:

a. Methyl (–CH₃). There are two methyl group attached.

b. Ethyl (–CH₂CH₃)

3. Locate the position of the substituent group attached to the compound by naming alphabetically.

a. The two Methyl (–CH₃) groups are located at carbon 2 and 3

b. The Ethyl (–CH₂CH₃) is located at carbon 4.

NOTE: The position of the Ethyl (–CH₂CH₃) group is the same from both side so we consider the lowest count for the methyl group.

4. Combine the above to obtain the name of the compound.

The name of the compound is:

4–ethyl–2,3–dimethylheptane

3 0

3 years ago

Explain the lava lamp

Dahasolnce [82]

A lava lamp is basically a hot liquid with chunks of the same hardend liquid and they rotate when they are heated

3 0

3 years ago