What is the chloride anion

Cl-

Explanation:

When chlorine reacts with other substances, it usually forms the chloride ion (Cl-). This is because it has seven valence electrons, and in order to gain a full octet, it has to gain one electron (which has a negative charge). For example, when it reacts with Sodium (Na), the product is table salt (NaCl) because chlorine takes one electron from sodium and becomes Cl-. Sodium also becomes Na+, because it loses one electron.

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%