Answer:
pH = 5.54
Explanation:
The pH of a buffer solution is given by the <em>Henderson-Hasselbach (H-H) equation</em>:
- pH = pKa + log
![\frac{[CH_3COO^-]}{[CH_3COOH]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BCH_3COO%5E-%5D%7D%7B%5BCH_3COOH%5D%7D)
For acetic acid, pKa = 4.75.
We <u>calculate the original number of moles for acetic acid and acetate</u>, using the <em>given concentrations and volume</em>:
- CH₃COO⁻ ⇒ 0.377 M * 0.250 L = 0.0942 mol CH₃COO⁻
- CH₃COOH ⇒ 0.345 M * 0.250 L = 0.0862 mol CH₃COOH
The number of CH₃COO⁻ moles will increase with the added moles of KOH while the number of CH₃COOH moles will decrease by the same amount.
Now we use the H-H equation to <u>calculate the new pH</u>, by using the <em>new concentrations</em>:
- pH = 4.75 + log
= 5.54
Answer:
C
Explanation:
the enthalpy of reaction is independent of the reaction path
Answer:
acetic acid, sodium hydroxide
Explanation:
A strong acid is an acid that ionizes in water to give all its hydrogen ion. Weak acid only ionize to a certain degree. Acetic acid (CH3COOH) only ionize to give one hydrogen ion despite having other hydrogen atom. This account for its weak nature as an acid as shown below:
CH3COOH <=> H^+ + CH3COO^-
A strong base is a base that ionizes in water to give all it hydroxide ion. Sodium hydroxide(NaOH) ionizes to give all its hydroxide ions. This make it a strong base as shown below;
NaOH <=> Na^+ + OH^-
Answer:
The correct answer is "Electrons are transferred in an ionic bond"
Explanation:
The covalent bond is the chemical bond between atoms where electrons are shared, forming a molecule. Covalent bonds are established between non-metallic elements, such as hydrogen H, oxygen O and chlorine Cl. These elements have many electrons in their outermost level (valence electrons) and have a tendency to gain electrons to acquire the stability of the electronic structure of noble gas. The shared electron pair is common to the two atoms and holds them together.
An ionic bond is produced between metallic and non-metallic atoms, where electrons are completely transferred from one atom to another. During this process, one atom loses electrons and another one gains them, forming ions. Usually, the metal gives up its electrons forming a cation to the nonmetal element, which forms an anion.
In conclusion, chemical bonds are made so that atoms can have their entire outer layer, and thus have a stable electronic configuration. In the ionic bond, when the metallic atom has only one electron in its outer layer and the non-metallic one needs an electron to complete its layer; The metallic atom seats its electron to the non-metallic one. In the same way, the electron is shared in the covalent bond in order to achieve equilibrium.
Then, the main differences between the two bonds are that the ionic bond occurs between two different atoms (metallic and non-metallic), while the covalent bond occurs between two equal atoms (non-metallic). And in the covalent bond there is an electron compartment, while in the ionic bond there is an electron transfer.
So, the correct answer is "Electrons are transferred in an ionic bond"
Answer:
frequency = 0.47×10⁴ Hz
Explanation:
Given data:
Wavelength of wave = 6.4× 10⁴ m
Frequency of wave = ?
Solution:
Formula:
Speed of wave = wavelength × frequency
Speed of wave = 3 × 10⁸ m/s
Now we will put the values in formula.
3 × 10⁸ m/s = 6.4× 10⁴ m × frequency
frequency = 3 × 10⁸ m/s / 6.4× 10⁴ m
frequency = 0.47×10⁴ /s
s⁻¹ = Hz
frequency = 0.47×10⁴ Hz
Thus the wave with wavelength of 6.4× 10⁴ m have 0.47×10⁴ Hz frequency.
