Draw the structure of the starting material needed to make 2‑methylhept‑3‑yne (or 2‑methyl‑3‑heptyne) using sodium amide in liquid ammonia, followed by 1‑bromopropane.

See explanation and image attached

Explanation:

2‑methylhept‑3‑yne can be made by the reaction of the compound shown in the image attached with soidamide in liquid ammonia and 1‑bromopropane.

The first step in the reaction is the deprotonation of the alkyne starting material by the amide ion.

This step is followed a nucleophilic substitution reaction of the alkyne with 1‑bromopropane to yield the 2‑methylhept‑3‑yne product.

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

the volume increases