Answer:
pH =3.8
Explanation:
Lets call the monoprotic weak acid HA, the dissociation equilibria in water will be:
HA + H₂O ⇄ H₃O⁺ + A⁻ with Ka = [ H₃O⁺] x [A⁻]/ [HA]
The pH is the negative log of the H₃O⁺ concentration, we know the equilibrium constant, Ka and the original acid concentration. So we will need to find the [H₃O⁺] to solve this question.
In order to do that lets set up the ICE table helper which accounts for the species at equilibrium:
HA H₃O⁺ A⁻
Initial, M 0.40 0 0
Change , M -x +x +x
Equilibrium, M 0.40 - x x x
Lets express these concentrations in terms of the equilibrium constant:
Ka = x² / (0.40 - x )
Now the equilibrium constant is so small ( very little dissociation of HA ) that is safe to approximate 0.40 - x to 0.40,
7.3 x 10⁻⁶ = x² / 0.40 ⇒ x = √( 7.3 x 10⁻⁶ x 0.40 ) = 1.71 x 10⁻³
[H₃O⁺] = 1.71 x 10⁻³
Indeed 1.71 x 10⁻³ is small compared to 0.40 (0.4 %). To be a good approximation our value should be less or equal to 5 %.
pH = - log ( 1.71 x 10⁻³ ) = 3.8
Note: when the aprroximation is greater than 5 % we will need to solve the resulting quadratic equation.
TNT has the molecular formula: C7H5N3O6. And hence, when reacted in oxygen gas, you get what is known as <span>combustion</span> reaction. the reaction is: <span><span>C7</span><span>H5</span><span>N3</span><span>O6</span>+<span>O2</span>→C<span>O2</span>+<span>N2</span>+<span>H2</span><span>O</span></span>
Substances that cannot be separated and found on a periodic table are elements.
B. Holocaust
your welcome
A map that shows the location of volcanoes is called a Geologic Map. This kind of map contains information about the geological history and condition of volcanic sites.
<h3>
What do Geologic Maps indicate?</h3>
Geologic maps indicate the following:
- the location of volcanos
- age of rock deposits found near the volcano
- which volcanoes are active and those that aren't
- types of rocks at these sites
- faults fracture etc.
Note that the map specific to the question is unavailable hence the general response.
Learn more about geologic maps at:
brainly.com/question/2773541
