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Molarity is mole divided by volume in litres.
0.5mol divide by 0.5L = 1M
The answer is SiO2
Since silicon has four valence electrons and each oxygen has 2, for every 1 silicon there must be 2 oxygen to fill in both element's outer shells satisfactorily. An alternative way to figure out the chemical formula is to simply swap the charges.
Silicon is a -4 and oxygen is a -2.
Oxygen's charge is brought down into subscript and set as the number of silicons in the chemical formula, making silicon Si2. Silicon's charge is brought down to make the number of oxygens in the chemical formula O4. The formula we have currently is Si2O4. Simplify it to get the empirical formula (divide by 2) and you get SiO2.
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