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:
P2≈393.609Kpa so I think the answer is 394 kPa
Explanation:
PV=mRT Ideal Gas Law
m and R are constant because they dont change for the problem. That means
PV/T=mR = constant
so P1*V1/T1=P2*V2/T2 and note that the temperatures are in absolute temperatures (Kelvin) because you can't divide by zero.
So P2 = P1*V1*T2/(V2*T1) = 101325 Pa * 700 mL * 303K/(200 mL*273K)
P2 = 393609 Pa
Elements are substances that are made up of the same atoms which are capable of taking part in a chemical reaction.
There are different types of elements which are represented by symbols gotten from the first letter or the first and any other letter in the name of the element.
Examples of elements include:
When two or more of these elements combine together through a chemical bond, it leads to the formation of compounds.
Example of a compound includes:
- NaCl: The element sodium combine, through electrochemical bonding, with another element chlorine to form the compound sodium chloride.
Learn more here:
brainly.com/question/17571315
Answer:
they causes climate change by trapping heat and also they contribute to respiratory diseases from smog and air pollution
