Question #b7ed9

1 Answer
Fleur
Oct 22, 2017

#"0.051 mol Co"#

Explanation:

There is no formula—all you need is the Periodic Table!

The Periodic Table indicates that there are about #"58.933 grams"# of cobalt in #"1 mole"# of it.

Thus, we can use the conversion factor #"58.933 g Co" / "1 mol Co"# or #"1 mol Co" / "58.933 g Co"#. In this case, we use the second one so that the #"g"# unit cancels out.

#"3.0" cancel("g Co") xx "1 mol Co" / ("58.933" cancel("g Co")) = "0.051 mol Co"#

Since the given information has only two significant figures, that's what we round to.

Related questions
Impact of this question
944 views around the world
You can reuse this answer
Creative Commons License