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.
Answer:
<h3>The answer is 7.85 g/mL</h3>
Explanation:
The density of a substance can be found by using the formula
volume = final volume of water - initial volume of water
volume = 13.91 - 12 = 1.91 mL
We have
We have the final answer as
<h3>7.85 g/mL</h3>
Hope this helps you
Answer:
<h3>The answer is 7.42 </h3>
Explanation:
The pH of a solution can be found by using the formula
![pH = - log [ { H_3O}^{+}]](https://tex.z-dn.net/?f=pH%20%3D%20-%20log%20%5B%20%7B%20H_3O%7D%5E%7B%2B%7D%5D)
From the question we have
We have the final answer as
<h3>7.42 </h3>
Hope this helps you
Answer:
Any of the six chemical elements that markup group1
of the periodic table.
Explanation:
(1) 25 ml of water at 95 degrees Celsius is your answer. Temperature is the average kinetic energy of the substance that it measures, therefore the highest temperature choice, aka #1, is your answer.
