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### Finding the amount of molecules in compounds using mole conversions

Posted: Fri Oct 16, 2020 9:51 pm
Could someone explain how 1 mol = 6.022 x 1023 atoms but can also equal 6.022 x 10 23 molecules? Also, there is a problem in the textbook that says to "Calculate the amount of urea molecules, OC(NH2)2 in 2.5 x 105 g of urea," but gives the answer (3.8 x 103) in moles. If 1 mol = 6.022 x 1023 molecules, shouldn't the answer be 2.3 x 1027 molecules?

### Re: Finding the amount of molecules in compounds using mole conversions

Posted: Fri Oct 16, 2020 10:16 pm
6.022x10^23 is a constant that can apply to anything, it's just an easier way of describing quantities of atoms or molecules without having to work with big, complicated numbers. Pretty much how kilo- means 1000 of whatever it is you're working with (grams, meters, etc.), a mole is just 6.022x10^23 of whatever you're working with (atoms, molecules, etc.). It just makes calculations and stuff easier since you can work with much smaller numbers. And yes, your conversion of moles of urea to molecules is correct.

### Re: Finding the amount of molecules in compounds using mole conversions

Posted: Fri Oct 16, 2020 11:48 pm
Hannah_Kim_1I wrote:Could someone explain how 1 mol = 6.022 x 1023 atoms but can also equal 6.022 x 10 23 molecules? Also, there is a problem in the textbook that says to "Calculate the amount of urea molecules, OC(NH2)2 in 2.5 x 105 g of urea," but gives the answer (3.8 x 103) in moles. If 1 mol = 6.022 x 1023 molecules, shouldn't the answer be 2.3 x 1027 molecules?

to answer the second part of your question. It might be a typo! But in the end they are the same value just in different units.

### Re: Finding the amount of molecules in compounds using mole conversions

Posted: Sat Oct 17, 2020 8:09 am
Along with Briannes reply, Avogadro's constant is exactly that, a constant that does not have specific units in terms of atoms, photons, molecules, or any other unit for measurement. This means it can be applied in many situations either to cancel out some units or to convert moles into molecules.