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[N-A-20]

The mass of 1.21 x10^20 atom 0f sulfur?
-How many moles of Hcl are represented by 1.0 x10^19 Hcl molecules?
-How many grams of CL2 can be prepared from the reaction of 16.0g of Mno2 and 30g of Hcl according to the following chemical equation??
- Calculate the mass of FeS formed when 9.42 g of Fe reacts with 8.50 g of S.

Fe(s) + S(s)  FeS(s)
.....