Calculate the pH of a 0.30 M NaF solution. The Ka value for HF is 7.2*10^-4
Answers
Kb = KaKb
1.00 x 10^-14 = 7.2 x 10^-4(x)
x = 1.39 x 10^-11
We now need to calculate the [OH¯] using the Kb expression:
1.39 x 10^-11 = x^2 / (0.30 - x)
The denominator can be neglected. Thus, x is 3.73 x 10^-6.
pOH = -log 3.73 x 10^-6 = 5.43
pH = 14-5.43 = 8.57
Answer:
pH=8.32
Explanation:
The relevant equilibrium for this problem is
F⁻ + H₂O ↔ HF + OH⁻
With a constant Kb of
Kb=
Kb=
To calculate the value of Kb we use the formula Kw=Ka*Kb, where Kw is the ionization constant of water, 1 * 10⁻¹⁴.
1 * 10⁻¹⁴ = 7.2*10⁻⁴ * Kb
Kb = 1.4 * 10⁻¹¹
So now we have
1.4 * 10⁻¹¹=
We make the assumption that x<<<0.30 M, so we can rewrite the equation of Kb as:
1.4 * 10⁻¹¹=
So [OH⁻]=2.05*10⁻⁶
- pOH=5.68
- pH = 14 - pOH
- pH=8.32
Related Questions
How many miles of a gas sample are in a 20.0 l container at 373kand 203 kpa? the gas constant is 8.31 l-kpa/m-k
The balanced chemical equation for the combustion of butane is: 2C2H2 + 5O2 CO2 + 2H2O 2CH4 + 5O2 2CO2 + 4H2O 2C4H10 + 13O2 8CO2 + 10H2O C4H10 + 12O2 4CO2 + 5H2O
3.Write the symbol of the element that has a charge of +1 when it has 71 electrons.
A solution of ammonia and water contains 1.80×1025 water molecules and 7.00×1024 ammonia molecules. How many total hydrogen atoms are in this solution?
B) The atomic orbitals overlap and electrons are shared between the atoms forming bonds.
C) A transfer of electrons forms ions which are electrostatically attracted forming bonds.
D) Orbital exchange occurs between the atoms to redistribute the electrons and form bonds.
Answers
Answer:
B
Explanation:
A) The sea of electrons only happen with metalic bond, a bond with two metalic elements.
B) As both elements in ammonia (N and H) are non-metals we don't observe an transfer of electrons, both elements share the number of electrons needed to stablize it (3 electrons for the N and 1 for the H).
C) To have a transfer of electrons, we need a bond between a metal and a non-metal, in this case, N and H are non-metals, so this doesn't happen.
D) The electrons are shared, only the electrons nothing happens between the orbitals.
How is electron movement related to covalent bonding in ammonia, NH3?
A) Electrostatic sharing in a sea of electrons around the atoms allows bonds to form.
B) The atomic orbitals overlap and electrons are shared between the atoms forming bonds.
C) A transfer of electrons forms ions which are electrostatically attracted forming bonds.
D) Orbital exchange occurs between the atoms to redistribute the electrons and form bonds.
The electron movement related to covalent bonding in ammonia, NH3 is The atomic orbitals overlap and electrons are shared between the atoms forming bonds. The answer is letter B.
Answers
Answers
Answer:
Yes.
Molecules always move in most objects, but in solids, they are extremely slow. Liquids move slower than gases, but move more than solids.
Final answer:
Molecules do move in a liquid, as they are free to slide past each other and change neighbors due to their mutual attraction. This allows liquids to flow and take the shape of their containers. The speed of this movement can depend on the mass of the molecules - lighter ones move and diffuse faster.
Explanation:
Yes, indeed, molecules do move in a liquid. This is due to the fact that liquids are typically in a more energetic state in which their particles can slide past one another and change neighbors. However, these particles remain closely held together by their mutual attraction which maintains the liquid's lack of shape conformity.
In liquids, unlike solids, the atoms or molecules are free to move around, which contributes to them being classified as a type of fluid. Due to their capacity to flow and rearrange their molecular structure, liquids deform easily when under stress. Once the force is removed, they don't return to their initial form, which is evidenced when a liquid takes the shape of a container it's put in.
Finally, the movement of these molecules is also somewhat dependent on their mass. Heavier molecules tend to move slower and are therefore slower to diffuse. In contrast, lighter molecules tend to move and diffuse faster.
Learn more about Molecule Movement in Liquids here:
#SPJ11
Answers
Answers
Most of the positively charged particles should bounce back at a range of angles as they collide with the atoms in the foil; only a few should pass straight through the foil.
(2) alpha particle, gamma ray, beta particle
(3) gamma ray, alpha particle, beta particle
(4) gamma ray, beta particle, alpha particle
Answers
Answer: The order of penetrating power from greatest to least is gamma ray, beta particle, alpha particle.
Explanation:
Penetration power is defined as the movement of particles or the ray through an object. It is directly proportional to the energy of the particle.
So, more is the energy of a particle, more will be its penetrating power.
We know that:
Gamma rays have the highest energy, followed by beta particle and then by alpha particle.
Thus, the ascending order of the penetration power of alpha rays, beta rays, and gamma rays will be:
Alpha rays < Beta rays < Gamma rays
Hence, the order of penetrating power from greatest to least is gamma ray, beta particle, alpha particle.