What is the weight percent of each O in SiO^2?

53.2%

Explanation:

Write the mass of the elements in your molecule:

Mass of Si in 1 mol SiO2 = 28.1g

Mass of O in 1 mol SiO2 = 16x2g = 32g

Now find the mass of your compound

Mass of compound = 28.1+32=60.1

Divide each element's mass by the mass of the compound to find the percent by mass following this formula:

% by mass = (mass of element/mass of compound) x 100

% by mass of oxigen = (32g/60.1) x 100

% by mass of oxigen = 53.2%

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