Use the following chemical equation to answer the question below. What if 0.060 g of magnesium completely react in 25 s, what is the average reaction rate in moles/second over that time interval? (Full question in screenshot)

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1 Answer
Nam D.
Mar 10, 2018

I get #9.88*10^-5 \ "mol/s"#.

Explanation:

I don't really think the chemical equation matters here... unless I'm missing something.

We got magnesium's atomic mass which is #24.3 \ "amu"#. An easy thing to remember is that atomic mass is the same thing as molar mass, so magnesium's molar mass will be #24.3 \ "g/mol"#.

There are #0.06 \ "g"# of magnesium atoms here, so there exist

#(0.06color(red)cancelcolor(black)"g")/(24.3color(red)cancelcolor(black)"g""/mol")~~2.47*10^-3 \ "mol"#

So, #2.47*10^-3# moles of magnesium decay in #25# seconds, and the average decay rate will therefore be

#(2.47*10^-3 \ "mol")/(25 \ "s")~~9.88*10^-5 \ "mol/s"#.

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