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2 years ago

Create a time that marks important events during the Precambrian Supereon.

Chemistry

2 answers:

Maurinko [17]2 years ago

8 0

I really hope this help!!

sesenic [268]2 years ago

4 0

Multiple Answers:

The earth started cooling and the outer edge of the planet solidified from molten lava to a solid crust. Water rained from the atmosphere and created oceans. The first form of life on our planet was created during the Archean eon in these oceans.

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The Great Pacific Garbage Patch is created by _____ currents. A. local B. surface C. deep ocean

Kamila [148]

The Great Pacific Garbage Patch is created by deep oceans. The Marine Debris is litter that ends up in oceans or other large bodies of water.

3 0

2 years ago

If 21.00 mL of a 0.68 M solution of C6H5NH2 required 6.60 mL of the strong acid to completely neutralize the solution, what was

Andru [333]

Answer:

pH = 2.46

Explanation:

Hello there!

In this case, since this neutralization reaction may be assumed to occur in a 1:1 mole ratio between the base and the strong acid, it is possible to write the following moles and volume-concentrations relationship for the equivalence point:

$n_{acid}=n_{base}=n_{salt}$

Whereas the moles of the salt are computed as shown below:

$n_{salt}=0.021L*0.68mol/L=0.01428mol$

So we can divide those moles by the total volume (0.021L+0.0066L=0.0276L) to obtain the concentration of the final salt:

$[salt]=0.01428mol/0.0276L=0.517M$

Now, we need to keep in mind that this is an acidic salt since the base is weak and the acid strong, so the determinant ionization is:

$C_6H_5NH_3^++H_2O\rightleftharpoons C_6H_5NH_2+H_3O^+$

Whose equilibrium expression is:

$Ka=\frac{[C_6H_5NH_2][H_3O^+]}{C_6H_5NH_3^+}$

Now, since the Kb of C6H5NH2 is 4.3 x 10^-10, its Ka is 2.326x10^-5 (Kw/Kb), we can also write:

$2.326x10^{-5}=\frac{x^2}{0.517M}$

Whereas x is:

$x=\sqrt{0.517*2.326x10^{-5}}\\\\x=3.47x10^-3$

Which also equals the concentration of hydrogen ions; therefore, the pH at the equivalence point is:

$pH=-log(3.47x10^{-3})\\\\pH=2.46$

Regards!

6 0

2 years ago

a gas in a container with a fixed volume was originally at a pressure of 317kpa and a temperature of 154k. what is the new press

goldfiish [28.3K]

<h2>Hello!</h2>

The answer is: 4.77atm

Since there's a fixed volume, we can use the the Gay-Lussac's Law which stablish a relation between the pressure and the temperature:

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

<em>P</em> is the volume of the gas

<em>t</em> is the temperature of the gas

<em>k </em>is the proportionality constant

We also have the following equation:

$\frac{P1}{T1}=\frac{P2}{T2}$

Where:

$P2=\frac{P1*T2}{T1}=\frac{317kPa*235K}{154K}=483.73kPa$

We are asked to find the pressure in atm, so we must convert 483.73kPa to atm:

$1kPa=0.009869atm$

Then,

$483.733kPa*\frac{0.009869atm}{1kPa}=4.77atm$

Have a nice day!

8 0

3 years ago

Please help with 1 chemistry question thank you!

ale4655 [162]

Here are the CORRECT names and molecular formulas

carbonate: $CO_3^{2-}$
bicarbonate: $HCO_3^{-}$

Choice 1 is incorrect

nitrite: $NO_2^{-}$
nitrate: $NO_3^{-}$

Choice 2 is incorrect

sulfite: $SO_3^{2-}$
sulfide: $S^{2-}$

Choice 3 is incorrect

By process of elimination, you can infer choice 4 is correct.

Actually, choice 4 is the only choice that displays the correct name and formula.

Have an awesome day! :)

7 0

2 years ago

When a bond is formed, energy is _ the atoms

Otrada [13]

"released from" the atoms

5 0

3 years ago