Answer:
- Last choice: <em><u>- 3.72°C</u></em>
Explanation:
The freezing point depression in a solvent is a colligative property: it depends on the number of solute particles.
The equation to predict the freezing point depression in a solvent is:
Where,
- ΔTf is the freezing point depression of the solvent,
- Kf is the cryoscopic molal constant of the solvent, and i is the Van'f Hoff factor, which is the number of ions produced by each unit formula of the ionic compound.
The calcualtions are in the attached pdf file. Please, open it by clicking on the image of the file.
The ph of the best buffer is 4.74
The given acetic acid is a weak acid
The equation of the pH of the buffer
pH = pKa + log ( conjugate base / weak acid ).
For best buffer the concentration of the weak acid and its conjugate base is equal.
pH = pKa + log 1
pH = pKa + 0
pH = pKa
given Ka = 1.8 × 10⁻⁵
pKa = - log ka
pH = -log ( 1.8 × 10⁻⁵ )
pH = 4. 74
Hence the pH of the best buffer is 4.74
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Answer:
A. Intramolecular interactions are generally stronger.
B. a. Only intermolecular interactions are broken when a liquid is converted to a gas.
Explanation:
<em>A. Which is generally stronger, intermolecular interactions or intramolecular interactions?</em>
Intramolecular interactions, in which electrons are gained, lost or shared, constitute true bonds and are one or two orders of magnitude stronger than intermolecular interactions.
<em>B. Which of these kinds of interactions are broken when a liquid is converted to a gas?</em>
When a liquid vaporizes, the intermolecular attractions are broken, that is, molecules get more separated. However, true bonds are not broken which is why the molecules keep their chemical identity.
Crust, the upper layer of the Earth, is not always the same. Crust under the oceans is only about 5 km thick while continental crust can be up to 65 km thick. Also, ocean crust is made of denser minerals than continental crust.
The tectonic plates are made up of Earth’s crust and the upper part of the mantle layer underneath. Together the crust and upper mantle are called the lithosphere and they extend about 80 km deep. The lithosphere is broken into giant plates that fit around the globe like puzzle pieces. These puzzle pieces move a little bit each year as they slide on top of a somewhat fluid part of the mantle called the asthenosphere. All this moving rock can cause earthquakes.
The asthenosphere is ductile and can be pushed and deformed like silly putty in response to the warmth of the Earth. These rocks actually flow, moving in response to the stresses placed upon them by the churning motions of the deep interior of the Earth. The flowing asthenosphere carries the lithosphere of the Earth, including the continents, on its back.
Answer:
The Mitochondria
Explanation:
Mitochondria are membrane-bound cell organelles that generate most of the energy required to power the cell's organic chemistry reactions. Energy created by the mitochondria is kept in a tiny molecule known as adenosine triphosphate (ATP).
