A reagent required 25 g of Magnesium sulfate MgSO4 * 7H2O (FW 245.5), only anhydrous crystal was available. How many grams of the anhydrous is needed to prepare this reagent?
The answer in the book is 12.17 grams
But how do you get that? I was way off.. I got something like 38.something.
2007-09-17 07:55:41 · 1 answers · asked by I_color_outside_the_lines 4 in Science & Mathematics ➔ Chemistry
duh..nevermind..it's ANhydrous, meaning I have to take the weight of the water OUT of the FW, which is 7(18) which is 119.5. Subtract that from the FW of 245.5 to get 119.5 then set up a simple ratio.
25g/245.5 g = x/ 119.5grams
x = 12.169 or 12.17 grams
God, I'm an idiot. I was ADDING it this whole time.
2007-09-17 07:58:19 · update #1
You are not an idiot. You are an intelligent human being. Chemistry problems are supposed to be hard. If they were easy, you wouldn't have to take a course.
2007-09-17 08:03:40 · answer #1 · answered by steve_geo1 7 · 0⤊ 0⤋