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:
H(aq) + NO3 (aq) + HF(aq)
Explanation:
In the given mixture of HNO3 (Nitric Acid) and HF (hydrofluoric acid) in water the major species present are H(aq) + NO3 (aq) + HF(aq).
On the reaction of HNO3 (Nitric Acid) and HF (hydrofluoric acid) in water , it will give a polar solution and will form a homogenous mixture.
Hence, the correct answer is "H(aq) + NO3 (aq) + HF(aq)".
Answer:
it keeps the heat in and the bugs and flys out
Explanation:
2. <span>(Note that sulfur is 2 columns from the right-hand end of the periodic table)</span>
Answer:
When I first began making bread, the science involved was always in the back of my mind. I had an idea of what occurred—my diagram for the chemical reactions
