Answer:
(2R,3S)-2-ethoxy-3-methylpentane
and
(2S,3S)-2-ethoxy-3-methylpentane
Explanation:
For this case, we will have 
as nucleophile. Also, this compound is also in excess. So, we will have as solvent 
a protic solvent. Therefore the Sn1 reaction would be favored.
The first step would be the carbocation formation followed by the attack of the nucleophile. In this case both isomers would be produced: R and S (see figure).
I can give you a clue of getting mass. if it is the atomic number is even multiply by 2 but if the atomic number is odd multiply by 2 and add 1
sodium atomic number = 11 so mass = 11*2 +1 = 23
oxygen. atomic number = 8 so mass = 8*2 = 16
carbon atomic number = 6 so mass = 6*2 = 12
New traits old traits to lose and save
1. Mitosis is a process where a single cell divides into two identical daughter cells (cell division).
2. Mitosis is important because it plays an important part in the development of embryos, and it is important for the growth and developemet of our body as well.
3. The four phases of mitosis are: Prophase, metaphase, anaphase, and telophase.
4. Two gap phases (G1 and G2); an S (for synthesis) phase, in which the genetic material is duplicated.
5. During S phase all of the chromosomes are replicated.
I hope that helps! c:
