Object B
Explanation:
Answer:
Explanation:
A) Number of pi bonds and if they are delocalized:
Determine the number of pi (π) bonds in the molecule. Pi bonds are formed by the overlap of p-orbitals in a double or triple bond.
Assess whether these pi bonds are delocalized. Delocalization occurs when electrons in pi bonds are not localized between just two atoms but are spread out over multiple atoms or regions within the molecule. This typically involves resonance structures in organic chemistry.
B) Number of sigma bonds and if they are localized:
Determine the number of sigma (σ) bonds in the molecule. Sigma bonds are formed by the head-on overlap of atomic orbitals in single bonds.
Assess whether these sigma bonds are localized. In most cases, sigma bonds are localized between two specific atoms, meaning they involve a direct bond between those atoms.
C) Number of hydrogen bonds and if they are polarized:
Determine the number of hydrogen bonds in the molecule. Hydrogen bonds are a special type of dipole-dipole interaction involving hydrogen atoms bonded to highly electronegative atoms (such as oxygen, nitrogen, or fluorine) and other electronegative atoms.
Assess whether these hydrogen bonds are polarized. Hydrogen bonds involve a difference in electronegativity between the hydrogen atom and the electronegative atom, creating a polar bond. The extent of polarization can vary depending on the specific atoms involved.
D) Number of covalent bonds and if they are ionic:
Determine the number of covalent bonds in the molecule. Covalent bonds involve the sharing of electrons between atoms.
Assess whether these covalent bonds are ionic. Covalent bonds are typically characterized by the sharing of electrons, while ionic bonds involve the complete transfer of electrons from one atom to another, resulting in ions. Covalent bonds are typically nonpolar or polar, while ionic bonds are highly polar.
Answer : A substance that can donate a pair of electrons to form a covalent bond is known as a(n) Lewis-base.
Explanation :
According to the Lewis acid-base theory,
Lewis acid : It is a substance that can accepts pairs of electrons to form a covalent bond.
Lewis-base : It is a substance that can donates pairs of electrons to form a covalent bond.
For example :
In this reaction, ion is Lewis-acid and ion is a Lewis-base. The ion donates electrons to ion to form .
Hence, a substance that can donate a pair of electrons to form a covalent bond is known as a(n) Lewis-base.
A substance that can donate a pair of electrons to form a covalent bond is known as a Lewis base. It is any substance that can donate a pair of nonbonding electrons. The Lewis theory suggests that acids react with bases to share a pair of electrons with no change of oxidation numbers of any atoms.
b. distillation
c. crystallization
d. chromatography
Answer:
69.3%
Explanation:
The question should read as follows:
A weak acid, HA, has a pKa of 4.357. If a solution of this acid has a pH of 4.005, what percentage of the acid is not ionized? Assume all H⁺ in the solution came from the ionization of HA.
The Henderson-Hasselbalch equation relates the pKa and pH of a solution to the ratio of ionized (A⁻) and unionized (HA) forms of a weak acid:
pH = pKa + log ([A⁻]/[HA])
Substituting and solving for [A⁻]/[HA]:
4.005 = 4.3574 = log([A⁻]/[HA])
-0.3524 = log([A⁻]/[HA])
[A⁻]/[HA] = 0.444/1
The percentage of acid that is not ionized (i.e. the percentage of acid in the HA form) is calculated:
[HA]/([A⁻] + [HA]) x 100% = 1/(1+0.444) x 100% = 69.3%
As you have not provided the options, still we can figure out the answer by understanding the key difference between saturated and unsaturated hydrocarbons.
SATURATED HYDROCARBONS are those hydrocarbons which only consist of a carbon carbon single bonds. All the bonds are sigma there are no pi bonds at all. Examples are shown below.
While, UNSATURATED HYDROCARBONS are those hydrocarbons which may contain either a double bond or triple bonds or both of them between the carbon atoms as shown below.
A saturated hydrocarbon has only single bonds, like methane (CH4), while an unsaturated hydrocarbon contains double or triple bonds, like ethene (C2H4).
To categorize a hydrocarbon as saturated or unsaturated, we need to look at the types of bonds it has. A saturated hydrocarbon, such as alkanes, has only single bonds between carbon atoms. For example, methane is a saturated hydrocarbon because it's formula, CH4, indicates only single bonds. On the other hand, an unsaturated hydrocarbon, such as alkenes and alkynes, contains double or triple bonds. An example of an unsaturated hydrocarbon is ethene (C2H4), an alkene which consists of a double bond between the two carbon atoms.
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b. Solution a must have a higher solute concentration than solution
b. Solution a and solution b must have the same concentration of solutes. Solution b must be pure water.
The answer is solution a must have a lower solute concentration than solution b.
That is when water is moving across a membrane from solution a into solution b, then solution a must have a lower solute concentration than solution b.
When solution a have a lower solute concentration than solution b, then water moves across a membrane from solution a into solution b.