Answer:
The correct answer is D
Explanation:
Many substances hold their molecules together in the liquid or solid bosom. This is due, in addition to the pressure and temperature conditions, by the forces of Van der Waals. These are still produced in nonpolar molecules by the movement of electrons through the molecules; in extremely short periods of time, their electrons "charge" towards one end of the molecule, producing small dipoles and keeping the molecules very close to each other.
A size dependent property is a physical property that changes when the size of an object changes.
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:
B as all the forces cancel out
Explanation:
20-20=0
25-25=0