1. 2.
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Questions
In a sample of sulfur weighing 4.07 g, (a) how many moles of
sulfur are present, and (b) what is the total number of sulfur atoms
in the sample?
Potassium-40 is one of the few naturally occurring radioactive
isotopes of elements of low atomic number. Its percent natural
abundance among K isotopes is 0.012%. How many 40K atoms
are present in 225 mL of whole milk containing 1.65 mg K/mL?
An analytical balance can detect a mass of 0.1 mg. What is the
total number of ions present in this minimally detectable quantity
of MgCl2?
The volatile liquid ethyl mercaptan, C2H6S, is one of the most
odoriferous substances known. It is sometimes added to natural
gas to make gas leaks detectable. How many C H S molecules
are contained in a 1.0-PL sample? (d = 0.84 g/mL.)
How many moles of F atoms are in a 75.0-ml sample of
halothane (C2HBrCIF3, d = 1.871 g/mL)? [H = 1, C = 12, F = 19, CI
= 35.5, Br = 80]
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