1. A compound has a molar mass of 80.0g has molecules that are tetratomic.
A.How many total atoms are present in a 120.0g sample of the compound?
B. How many molecules are present in a 40.0g sample of the compound?
2.what mass, in grams, of nickel is present in a 25.00g sample of nickel ore that is 77.25% NiS? Assume that impurities present do not contain any nickel.
2007-11-01 17:12:18 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
1. For either part, you first need to convert mass to moles. Do this by dividing weights by 80 g/mole.
For A. multiply moles * 4 * 6.02x10^23
For B. mulltiply moles * 6.02 x 10^23
2. Find mass of pure NiS in ore sample.=
.7725*25. Call result=W. Then find mole wt of NiS and atomic wt of Ni.
Mass of Ni = atomic wt Ni/ mole wt NiS * W.
2007-11-01 17:22:08 · answer #1 · answered by cattbarf 7 · 0⤊ 0⤋