Question

A compound consists of 75% magnesium and 25% oxygen. Find the empirical formula.

Answer 1

Answer:

% Composition of elements:

• Magnesium = 75%
• Oxygen = 25%

Atomic mass of given elements:

• Magnesium = 24 g
• Oxygen = 16 g

Now, divide % composition by Atomic mass:

$\footnotesize\implies Mg = \dfrac{\% \: Composition}{Atomic \: mass} = \dfrac{75}{24} = \bf 3.125$

$\footnotesize\implies O = \dfrac{\% \: Composition}{Atomic \: mass} = \dfrac{25}{16} = \bf 1.5625$

Simplest Ratio:

$\footnotesize\implies Mg = \dfrac{3.125}{1.5625} = 2$

$\footnotesize\implies O = \dfrac{1.5625}{1.5625} = 1$

Empirical Formula:

$\footnotesize\implies \underline{ \boxed{ \red{ \bf Empirical \: Formula = Mg_2O}}}$