(HELP I HAVE 10 MINS TO TURN IN) why is the nervous system in the human body a system?

Blue colour of cupric nitrate on strongly heating gives gives black cupric oxide powder along with oxygen gas and nitrogen dioxi

Zinaida [17]

Please see the image.

6 0

3 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

3 years ago

Which sequence represents the relationship between pressure and volume of an ideal gas as explained by the kinetic-molecular the

Svetlanka [38]

<h2>Answer : Option C) Smaller volume - crowded particles - more collisions - high pressure</h2><h3>Explanation : </h3>

The kinetic molecular theory of gases explains that if there is small volume of gas there will be more crowding of the gas molecules inside the container. The crowded gas molecules will collide with each other and also with the walls of container as a result, exchange of energies will take place. Which will increase the pressure inside the container, and will raise the pressure than the initial pressure.

8 0

3 years ago

Read 2 more answers

Express in scientific notation. Remember, M must be a number such that 1 -<br><br><br> 0.000000000000013= ____

Alex

Answer:

A) 1.3 * 10^-13

Explanation:

0.000000000000013 = 1.3 * 10^-13

5 0

2 years ago

Which surface ocean currents has the warmest water