How many grams of a stock solution that is 87.5 percent H2SO4 by mass would be needed to make 275 grams of a 55.0 percent by mass solution?

Question

sleepyjess · Answer

@Abhisar help pwease? *puppy face*

matt101 · Answer

We're diluting the first solution to make the second solution. This means both solutions will contain the same amount of H2SO4 (it's the concentration of it that changes). If you look at it this way, it's easy to find the unknown mass. Call this unknown mass m.

m * 0.875 = 275 g * 0.55  -->  m = 173 g

What I'm saying here is 87.5% of the mass of the first solution needs to be the same as 55% of the mass of the second solution, because you're using the same amount of H2SO4 in both. Does that make sense?

PS. Sorry it took so long to write. Had to edit my answer a couple times so it wouldn't sound too confusing :P