How do I convert grams to moles to mole ratios? #"Mg" + "O"_2 - "MgO"#
16.2g+10.67g=26.86g

Question

How do I convert grams to moles to mole ratios? #"Mg" + "O"_2 -> "MgO"#
16.2g+10.67g=26.86g

Ellie Andrews · Accepted Answer

Here's how you can do that.

Make sure the chemical equation is balanced first. #color(blue)(2)"Mg"_ ((s)) + "O"_ (2(g)) -> color(purple)(2)"MgO"_ ((s))# Notice that the reaction consumes #color(blue)(2)# moles of magnesium and #1# mole of oxygen gas and produces #color(purple)(2)# moles of magnesium oxide. Thus, you could say that each chemical species involved in this reaction needs to have a certain number of moles in order to satisfy #"moles Mg " : " moles O"_2color(white)(.): " moles MgO"# #color(white)(aaaacolor(blue)(2)aaaa. color(black)(":") aaaacolor(black)(1) aaaaacolor(black)(":") aaaaacolor(purple)(2)# You can now use molar mass to convert grams to moles. In this instance, you have #M_ ("M Mg") = "24.3050 g mol"^(-1)# #M_ ("M O"_2) = "32.0 g mol"^(-1)# #M_ ("MgO") = "40.3050 g mol"^(-1)# Use the element's molar mass as a conversion factor to convert the mass of magnesium from grams to simply. #16.2 color(red)(cancel(color(black)("g"))) * "1 mole Mg"/(24.3050 color(red)(cancel(color(black)("g")))) = "0.6665 moles Mg"# Apply the same procedure to the oxygen gas sample. #10.67 color(red)(cancel(color(black)("g"))) * "1 mole O"_2/(32.0color(red)(cancel(color(black)("g")))) = "0.3334 moles O"_2# Lastly, apply the same procedure to the magnesium oxide. #26.86 color(red)(cancel(color(black)("g"))) * "1 mole MgO"/(40.3050color(red)(cancel(color(black)("g")))) = "0.6664 moles MgO"# So, you know that when #0.6665# moles of magnesium react with #0.3334# moles of oxygen gas, you get #0.6664# moles of magnesium oxide. Due to rounding and differences in the values used for the molar masses of the three chemical species, the values do not exactly match.

Kai Bowman · Answer

undefined 1. Calculate moles of Mg: $0.666$ moles
2. Calculate moles of $O_2$: $0.333$ moles
3. Determine mole ratio: $Mg : O_2 = 2 : 1$ (simplified from $2 : 2$)

How do I convert grams to moles to mole ratios? #"Mg" + "O"_2 -&gt; "MgO"# 16.2g+10.67g=26.86g

How do I convert grams to moles to mole ratios? #"Mg" + "O"_2 -> "MgO"# 16.2g+10.67g=26.86g