The Ka : 1.671 x 10⁻⁷
<h3>Further explanation</h3>
Given
Reaction
HA (aq) + H2O (l) ←→ A- (aq) + H3O+ (aq).
0.3 M HA
pH = 3.65
Required
Ka
Solution
pH = - log [H3O+]
![\tt [H_3O^+]=10^{-3.65}=2.239\times 10^{-4}](https://tex.z-dn.net/?f=%5Ctt%20%5BH_3O%5E%2B%5D%3D10%5E%7B-3.65%7D%3D2.239%5Ctimes%2010%5E%7B-4%7D)
ICE method :
HA (aq) ←→ A- (aq) + H3O+ (aq).
0.3 0 0
2.239.10⁻⁴ 2.239.10⁻⁴ 2.239.10⁻⁴
0.3-2.239.10⁻⁴ 2.239.10⁻⁴ 2.239.10⁻⁴
![\tt Ka=\dfrac{[H_3O^+][A^-]}{[HA]}\\\\Ka=\dfrac{(2.239.10^{-4}){^2}}{0.3-2.239.10^{-4}}\\\\Ka=1.671\times 10^{-7}](https://tex.z-dn.net/?f=%5Ctt%20Ka%3D%5Cdfrac%7B%5BH_3O%5E%2B%5D%5BA%5E-%5D%7D%7B%5BHA%5D%7D%5C%5C%5C%5CKa%3D%5Cdfrac%7B%282.239.10%5E%7B-4%7D%29%7B%5E2%7D%7D%7B0.3-2.239.10%5E%7B-4%7D%7D%5C%5C%5C%5CKa%3D1.671%5Ctimes%2010%5E%7B-7%7D)
Answer: at higher temperatures.
Justification:
1) Soda have CO₂ dissolved. Carbonation consists on that: dissolving CO₂ into water, leading to carbonated water.
2) The solution of a gas into a liquid is inversely related to the temperature: the lower the temperature the more gas gets dissolved.
So, in the manufacturing of soda, the CO₂ is added in cool water in a cool environment.
3) So, the higher the temperature after the soda is delivered, the more gas will be liberated when you open the can.
Answer: The new penny is not pure copper
Explanation:
Density 
is defined as a relation between the mass 
and the volume 
:
Now, we are told the density of pure copper is:
And we are given the mass and volume of the new penny, with which we can calculate its density:
As we can see the density of this penny is not equal to the density of pure copper, hence the new penny is not pure copper.
Answer:
Noble gases
Explanation:
Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table in the figure below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).18 Jun 2021
Lee? The verb should be in the el/Ella/usted form
