Answer:
A) homotopic and B) enantiotopic
Explanation:
Protons chemically equivalent are those that have the same chemical shift, also if they are interchangeable by some symmetry operation or by a rapid chemical process.
The existence of symmetry axes, Cn, that relate to the protons results in the protons being homotopic, that is chemically equivalent in both chiral and aquiral environments.
The existence of a plane of symmetry, σ, makes the protons related by it, are enantiotopic and these protons will only be equivalent in an aquiral medium; if the medium is chiral both protons will be chemically NOT equivalent. The existence of a center of symmetry, i, in the molecule makes the related protons through it enantiotopic and therefore chemically only in the aquiral medium.
Diastereotopic protons cannot be interconverted by any symmetry operation and they are different, with different chemical displacement.
Answer:
1.67 M
Explanation:
The following data were obtained from the question:
Initial volume (V1) of solution = 250 mL
Initial Molarity (M1) of solution = 0.5 M
Final volume (V2) of solution = 75 mL
Final Molarity (M2) of solution =?
Thus, we can obtain the final molarity of the solution by using the following formula:
M1V1 = M2V2
0.5 × 250 = M2 × 75
125 = M2 × 75
Divide both side by 75
M2 = 125 /75
M2 = 1.67 M
Thus, the new Molarity of the solution is 1.67 M.
Answer:
21
Explanation:
bcecause thats the only one
Answer: double replacement
Explanation:
Answer:
Ca^2+
Explanation:
As we know, more energy is required to remove an electron from a positively charged ion than is required to remove an electron from a neutral atom. Hence, the second ionization energy of calcium is greater than its first ionization energy.
However, the third and fourth ionization energies of calcium are much higher than the second ionization energy because they involve removal of electrons from an inner filed shell. This process requires a lot of energy and is often not feasible.
Hence, the most common ion of calcium must be Ca^2+ where only two electrons are removed from calcium.