MCu: 63,5 g/mol
4 × mCu = 63,5×4 = 254 g
254g ------ 0,39%
Xg ---------- 100%
X = (254×100)/0,39
X = 65128,2 g/ mol <<<< molar mass
When a solute is completely dissolved in a solvent, a solution is formed.
The mass is 132.0384 grams.
The answer would be A. troposphere