please help me
2006-08-28 20:33:14 · 3 answers · asked by kat 2 in Science & Mathematics ➔ Chemistry
Avogadro determined that the same number of atoms or molecules are found in every mole of a substance. This number is called Avogadro's Number, which is about 6.02 X 10^23 (10 with 23 zeros). One mole has a mass equal to the moleculaer weight of a substance.
3 X 10^22 molecules is 0.0498 moles. The molecular weight of SO3 is 80.06 grams/mole.
0.0498 moles X 80.06 grams/mole = 3.987 grams or about 4 grams.
2006-08-28 21:06:45 · answer #1 · answered by Richard 7 · 68⤊ 0⤋
Avogadro's constant is 6.0221415 X10**23 . This means, this many molecules of SO3 would weigh 80.0632g .
You are asking about 3 x 10**22, which is 1/20 of an Avogadro's constant. Therefore, the mass of these would be 1/20 of 80.0632g, or about 4.00g
2006-08-29 03:41:37 · answer #2 · answered by don.giovanni 3 · 0⤊ 2⤋
one mole of SO3 is 80 grams. 80 grams of SO3 has 6.02X 10*23 molecules so, 3X10*22 molecules of SO3 would weight at about 3.98 grams/ 4 grams. ( The criss-cross method)
2006-08-29 04:02:55 · answer #3 · answered by pip 2 · 1⤊ 0⤋