1How many grams of carbon in 2.408 x 10^22 atoms of carbon?So when I did my calculations I came up with 4.803 x 10^45 g of carbon2In 25 kg of aluminum sulfate, how many atoms of aluminum are there? 2 atoms of aluminum
I'm doing this from ancient memory only, so here goes: Question 1: 6.022 x 10^23 atoms of carbon is a mole of carbon (just kind of like 128 ozsof gas is a gallon of gas)You need this many atoms for the amount of substance to equal its atomic weight in grams (in this case, 12.011 for carbon; we're using SI units, of course)You have only 2.408 x 10^22 atoms, which is a bit less than a moleDivide a mole into this, and you end up 0.0399867 mole, or rounded, 3.999 x 10^-2 moleThat's just under 4% of one mole, so you have just under 4% of 12.011 gramsThat comes out to 0.4803g of carbonYour math is correct, except for the exponential (should be 4.803 x 10^-1g)Question 2: You're correctAl2(SO4)3 has two aluminum atomsHard to bear this out, given the constraints of not being able to use super or subscripts in this font.
