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:
Cl
Explanation:
chlorine (2,8,7) is a non metal with highest electronegativity. Hence, it is most likely to form a negative ion with charge −1.
I hope it helps you
Answer:
Explanation:
Hello there!
In this case, according to the Dalton's law, which explains that the total pressure of a gaseous system equals the sum of the partial pressures of the gases composing, for the gaseous mixture composed by oxygen, nitrogen and carbon dioxide it would be possible to write:
Now, given the pressure of the system and those of oxygen and nitrogen, we calculate that of carbon dioxide as shown below:
Best regards!
Answer:
option C = Reactant: 4NH₃ + 6NO → product: 5N₂ + 6H₂O
Explanation:
Chemical equation:
NH₃ + NO → N₂ + H₂O
Balanced chemical equation:
4NH₃ + 6NO → 5N₂ + 6H₂O
Ammonia is react with nitrogen mono oxide and produced nitrogen and water.
Ammonia and nitrogen monoxide are reactants while water and nitrogen are product.
Four number of moles of ammonia react with six nitrogen monoxide and produced five mole of nitrogen and six mole of water.
