Question

How many grams of Mg are needed to react completely with 3.80 L of a 2.50 M HF solution?

Answer 1

You need a balanced chemical equation Mg(s) + 2HF(aq)--> MgF2(s) + H2(g)

3.80L x (2.50 mol HF/ 1L) x (1 mol Mg/ 2 mol HF) x (24.3g Mg/ 1 mol Mg) = 115gMg.... To three significant digits