In an experiment 2.750 g of magnesium is reacted with 2.571 g of oxygen gas according to the equation:
Mg + O2 ==> MgO.
What mass of the other reactant is in exess?
You need equal number of moles of each. Which has the excess?
moles Mg=2.750/molmassMg
moles O2=2.571/32
One will have more than needed.(30*1.50)D+ (70+35)I=25500(30*1.50)D+ (70+35)I=25500
To determine which reactant is in excess, we need to calculate the number of moles of each reactant based on their masses.
First, we calculate the moles of magnesium (Mg):
moles Mg = mass of Mg / molar mass of Mg
moles Mg = 2.750 g / 24.31 g/mol
Next, we calculate the moles of oxygen gas (O2):
moles O2 = mass of O2 / molar mass of O2
moles O2 = 2.571 g / 32 g/mol
Now we compare the moles of each reactant. The reactant that has more moles than needed is in excess.
If the moles of Mg is greater than the moles of O2, then Mg is in excess.
If the moles of O2 is greater than the moles of Mg, then O2 is in excess.
Compute the moles of Mg and O2 to determine which reactant is in excess.