Which criteria should materials of a technological design meet? check all that apply. they must be imported. they must be affordable. they must be naturally made. they must be durable. they must be available.

They must be affordable, durable, and available.

Explanation:

One is familiar with the fact that the materials would get exposed due to spontaneous uses. Thus, they become vulnerable to tear and wear as the time duration goes by. One of the characteristics, that is, durability makes sure that the substances thrive for various years, and offer great service to the masses. In supplementation to this, the substances should also be cost-effective and easily available.

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%

b.final