Question

What is the percent by mass of magnesium inMgO a)20% b)50% c)40%d)60%

Answer 1

d) 60%

Step-by-step explanation:

Given the chemical formula;

MgO = Magnesium oxide.

First of all, we would determine the relative molecular mass (RMM) of MgO.

Atomic mass of Mg = 24

Atomic mass of O = 16

RMM (MgO) = 24 + 16 = 40 g/mol

Next, we would find the percent by mass of magnesium (Mg);

% Mg = 24/40 * 100

% Mg = 2400/40

% Mg = 60 percent.