The mass of MgO is 1.04 g in a reaction. How many moles of MgO were used?

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Answer 1 · 2018-04-04T13:55:06

#2.58*10^-2# moles

Magnesium oxide's molar mass is #40.3044 \ "g/mol"#. So here,

#(1.04color(red)cancelcolor(black)"g")/(40.3044color(red)cancelcolor(black)"g""/mol")~~2.58*10^-2 \ "mol"#

of magnesium oxide were used.

Answer 2 · 2018-04-04T13:59:02

0.03 moles

#n=m/(mm)#

where:
n= number of moles
m= mass
mm= molar mass

SO

number of moles
=#1.04/ (16+24.31)#

=#1.04/40.31#

=#0.03# moles