What is the mass of #3.7 * 10^20# molecules of Rubidium Phosphate? #(Rb_3PO_4)#

1 Answer
May 28, 2018

Answer:

Approximately #2.16*10^-1 \ "g"=0.216 \ "g"#

Explanation:

We first convert to moles of #Rb_3PO_4#. In a mole of a substance, there'll be #6.02*10^23# units of that substance.

So, here we have:

#(3.7*10^20color(red)cancelcolor(black)(Rb_3PO_4 \ "molecules"))/(6.02*10^23color(red)cancelcolor(black)(Rb_3PO_4 \ "molecules")"/mol")~~6.15*10^-4 \ "mol"#

Now to find the mass, we multiply by its molar mass, which is #351.3748 \ "g/mol"#.

#6.15*10^-4color(red)cancelcolor(black)"mol"*(351.3748 \ "g")/(color(red)cancelcolor(black)"mol")~~2.16*10^-1 \ "g"#