MgMg and O_2O2 react in a 2.1 molar ratio. 2 moles M_gMg = 1 mole O_2O2. If a reaction used 32.5 g of O_2O2, how many g of MgMg reacted?

1 Answer
Mar 16, 2016

"49.4 g of Mg"49.4 g of Mg reacted.

Explanation:

Step 1. Calculate the moles of "O"_2O2.

32.5 cancel("g O"_2) × ("1 mol O"2)/(32.00 cancel("g O"2)) = "1.016 mol O"_2

Step 2. Use the molar ratio to calculate the moles of "Mg".

1.016 cancel("mol O"_2) × "2 mol Mg"/(1 cancel("mol O"_2)) = "2.031 mol Mg"

Step 3. Calculate the mass of "Mg".

2.031 cancel("mol Mg") × ("24.30 g Mg")/(1 cancel("mol Mg")) = "49.4 g Mg"

The reaction required "49.4 g Mg".