Answer:
The open system evaporates the solvent in the solution
Explanation:
An open system is a system in which exchange of materials and energy can occur. If a TLC set up is left open, then the set up constitutes an open system.
During TLC, the sample is dotted on the plate and inserted into a suitable solvent. The solvent moves up the plate and achieves the required separation of the mixture.
Most of these solvents used used TLC are volatile organic compounds. Therefore, if the TLC set up is left open, the solvent will evaporate leading to poor results after running the TLC experiment.
Answer:
Number of molecules = 2.61 x 10²³
Explanation:
Given:
Volume of tetra-chloride = 42 ml
Density = 1.59 g/ml
Find:
Number of molecules
Computation:
Mass = Volume of tetra-chloride x Density
Mass = 42 x 1.59
Mass = 66.78
Molecular mass of tetra-chloride = 154 g/mol
Moles = 66.78 / 154
Moles = 0.4337
0.4337 mole = 0.4337 x Avogadro number
0.4337 mole = 0.4337 x 6.022 x 10²³
Number of molecules = 2.61 x 10²³
The correct answer is B.
Strong acids completely dissociates to give hydrogen ions . Weak bases can only partially dissociate to give hydroxide ions .
Therefore when equal amounts of acid and base are mixed, while Acid is completely dissociated and gives out hydrogen ions but base only gives out a fraction of hydroxide ions.
Therefore number of hydrogen ions in the solution will be higher than hydroxide ions, resulting in an acidic pH. Therefore pH <7
Answer:
The answer is Inductive effect
Explanation:
To determine the acidity or alkalinity of an organic compound. We have to keep in mind that the whole analysis is based on the comparison between the compounds, and we must work with the conjugated base of the molecule. Keeping in mind, the more unstable the base, the less acidic the molecule is. Thus, to determine instability, the Inductive Effect of the molecule can be used.
This type of effect occurs when atoms of different electronegativities are linked or very close in the compound. The most electronegative atom has a tendency to bring electrons close to it, thus creating a dipole. This dipole can have a stabilizing effect on the molecule, as it “relieves” the excessive charge on some occasions, better accommodating the charges.
However, in some cases, instead of chains with chlorine radicals, we may have chains with methyl radicals. This has a major impact on the inductive effect, keeping in mind that alkyl groups are electron donors.
