Mass, Moles, Number Conversions?

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Mass, Moles, Number Conversions?

Calculate the mass of 3.37×1021 molecules of copper(I) carbonate.
Calculate the number of lithium ions in 3.53 g lithium sulfate.

2007-09-29 06:40:14 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry

2 answers

The key is to use Avogadro's number, 6.02 x 10E23 particles / mole.

In the first problem, divide by Avo's to get the number of moles. Then multiply by the molcular mass of the compound to get grams.

In the second problem it is the reverse. Divide by the molecular mass to get moles and then multiply by Avo's number

2007-09-29 06:45:23 · answer #1 · answered by reb1240 7 · 2⤊ 0⤋

GMM of Cu2CO3 = 127+60 = 187 g

1 mole contains 6.023x10^23 units.

2007-09-29 14:00:20 · answer #2 · answered by ag_iitkgp 7 · 0⤊ 0⤋