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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: QuarkLept on September 28, 2020, 07:27:21 PM

Title: Connection between Avogadro’s number and molar mass
Post by: QuarkLept on September 28, 2020, 07:27:21 PM

I don’t understand the connection between Avogadro’s number and molar mass. I know that 1 mole is 6.022 x 10^23 particles, but 1 mole is also the atomic mass of 1 atom? I just don’t understand the point of Avogadro’s number if we can just use atomic and molar mass instead.

Title: Re: Connection between Avogadro’s number and molar mass
Post by: chenbeier on September 29, 2020, 02:00:26 AM

The first statement  1 mole is 6,023 * 10²³  particles is correct.
But the statement 1 mole is the molar mass of one atom is wrong.
According the first statement the molar mass is the mass of  6,023 *10²³  atoms.

Title: Re: Connection between Avogadro’s number and molar mass
Post by: Borek on September 29, 2020, 03:09:43 AM

My bet is you are getting confused by the fact the same number depict both molar mass when expressed in grams and atomic mass when expressed in a.m.u. Same number doesn't mean same mass! (Think how 10 ounces is not the same thing as 10 kilograms). Note that to get mass of one atom in grams you have to multiply mass expressed in a.m.u. by 1.66×10^-27 g.