And then I'm going to use my mole ratio.

I see that for every one mole of TiCl4,

it's going to react with two moles of magnesium and

then I can use the molar mass of magnesium 24.31 grams

per mole of magnesium in order to find the grams of magnesium.

And so I'm going to go through and check that my units cancel out correctly.

So, grams of TiCl4, moles of TiCl4,

moles of magnesium and I'm left with grams of magnesium.

Which is exactly what's being asked for in the problem.

So, now I can do the calculation and find that amount.

Remember that it doesn't matter which side of the equation the values are on.

As long as we know the coefficients from a balanced chemical equation,

we can set up that mole to mole ratio When I do the calculation,

I find that it's 21.4 grams of magnesium are going to be

needed in order to completely consume the 83.6 grams of TiCl4.