Question

Determine the percent composition of all elements in enstatite, MgSiO3, a mineral found in Earth's crust.

Answer 1

Magnesium:
Mg molar mass: 24.3050
You have one atom of Mg so, 24.211% (mass percent)

Silicon:
Si molar mass: 28.0855
You have one atom of Si so, 27.977% (mass percent)

Oxygen:
O molar mass: 15.9994
You have three atoms so, 47.812% (mass percent)

Answer 2

Step-by-step explanation:

Percentage of an element in a compound:

`\frac{\text{Number of atoms of element}* \text{Atomic mass of element}}{\text{molecular mass of compound}}* 100`

Mass of magnesium atom = 24 g/mol

Mass of silicon atom = 28 g/mol

Mass of oxygen atom = 16 g/mol

Molar mass of
`MgSiO_3` =24 g/mol+28 g/mol+3 × 16 g/mol=100 g/mol

Composition of all elements in enstatite,
`MgSiO_3`

Percentage of magnesium :

`(1* 24 g/mol)/(100 g/mol)* 100=24\%`

Percentage of silicon:

`(1* 28 g/mol)/(100 g/mol)* 100=28\%`

Percentage of oxygen:

`(3* 16 g/mol)/(100 g/mol)* 100=48\%`