empirical to molecular formula  [ENDORSED]

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dtolentino1E
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empirical to molecular formula

Postby dtolentino1E » Tue Oct 08, 2019 11:30 am

hi!

so when you are trying to calculate the molecular formula and you are given the empirical formula and the mass of whatever compound, i know that you're supposed to calculate the molar mass from the empirical formula and find a ratio between the masses, then multiply by whatever number it comes out to be.

can someone tell me which mass (molar or the given one in the equation) is divided by the other?

Rida Ismail 2E
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Re: empirical to molecular formula

Postby Rida Ismail 2E » Tue Oct 08, 2019 11:38 am

Ok, so your question confuses me just a bit. But I want to give you a list of steps which should hopefully answer your question.

If the question gives you an empirical formula or you just calculated the empirical formula, you would then need to calculate the empirical formula of the empirical formula. The question needs to give you the molar mass of the molecular formula. From the molar mass of the molecular formula, you can find out the ratio of atoms in the empirical vs the molecular by the empirical molar mass divided by the molecular molar mass. This will give you the ratio and you can multiple each atom in the empirical formula by this number.

Sam McNeill 1E
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Re: empirical to molecular formula  [ENDORSED]

Postby Sam McNeill 1E » Tue Oct 08, 2019 12:11 pm

The molecular formula molar mass is divided by the empirical's, and then you multiply the empirical's subscripts by whatever the quotient is.

LNgo 1G
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Re: empirical to molecular formula

Postby LNgo 1G » Tue Oct 08, 2019 3:55 pm

You divide the given molar mass by the empirical mass. The empirical mass will always be smaller than the molecular mass because it is the smallest ratio of the atoms so you can try to remember that you divide by the smaller number.

Kallista McCarty 1C
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Re: empirical to molecular formula

Postby Kallista McCarty 1C » Tue Oct 08, 2019 3:59 pm

You divide the given molar mass of the molecular formula by the calculated molar mass of the empirical formula that you found!

Nathan Nakaguchi 1G
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Re: empirical to molecular formula

Postby Nathan Nakaguchi 1G » Tue Oct 08, 2019 4:45 pm

I believe it goes: (Molar Mass Given)/(Empirical molar mass)= Number you need to multiply the empirical formula to get the molecular formula.

britthanul234
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Re: empirical to molecular formula

Postby britthanul234 » Tue Oct 08, 2019 4:57 pm

You simply divide the molar mass by the empirical mass.

Kelsey Ash 1D
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Re: empirical to molecular formula

Postby Kelsey Ash 1D » Tue Oct 08, 2019 11:35 pm

You divide the given molar mass (the mass of the molecular formula) by the molar mass of the empirical formula. Whatever the product of that equation is is the number you multiply the empirical formula by.

Chem_Mod
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Re: empirical to molecular formula

Postby Chem_Mod » Wed Oct 09, 2019 12:28 am

LNgo 14A wrote:You divide the given molar mass by the empirical mass. The empirical mass will always be smaller than the molecular mass because it is the smallest ratio of the atoms so you can try to remember that you divide by the smaller number.


Remember that in some cases the molecular formula and the empirical formula are the same. In that situation, both masses would be equal.

AChoudhry_1L
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Re: empirical to molecular formula

Postby AChoudhry_1L » Sat Oct 12, 2019 6:28 pm

When finding the ratio, divide the total molar mass by the empirical mass. Sometimes, this will give you 1 and that means that the molar mass is the same as the empirical mass and therefore, the formulas are the same as well.


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