A Tricky Problem 1. If 4.74g of magnesium is reacted with 4.000L of 2.500mol/L hydrochloric acid, calculate the change in temperature for the hydrochloric acid. I think the equation is Mg(s) + HCl(l) ------> MgCl(2)(l) + H(2)(g) I know these two equations will be in use. 1. Q=mTc 2. H=Q/n I suppose I find the mol of magnesium. 4.74g x 1mol/24.305g =0.195mol That's all I know about this, I don't know the next steps. Thank You.