Answer:
A. a system that can be affected by the outside environment, by an exchange of matter or energy
<span>the molar mass of a compound is the sum of the products of the atomic masses by the number of atoms of the element.
molar mass of Na</span>₂SO₄<span> is - 142 g/mol.
1 mol of </span>Na₂SO₄<span> has a mass of 142 g.
In 1 mol of </span>Na₂SO₄<span> the mass of Na is 23 g/mol x 2 = 46 g.
Mass of Na in 1 mol of </span>Na₂SO₄ is - 46 g
mass of Na in 0.820 mol of Na₂SO₄ - 46 g /1 mol x 0.820 mol = 37.72 g.
mass of Na is 37.72 g
1.strong acid: 2
2.weak acid:6
3.strong base:13
4.weak base:8
5.neutral:7
<span>FeCl3+ H2O --> Fe(OH)3 + 3 HCl the reaction will cause the least temprature change</span>
