A 20 wt % solution of sulfuric acid in water is to be enriched to a 60 wt % sulfuric acid solution by adding pure sulfuric acid. 

a. How much pure sulfuric acid should be added?

b. If the 20 wt % solution is available at 5°C, and the pure sulfuric acid at 50°C, how much heat will have to be removed to produce the 60 wt % solution at 70°C? How much heat will have to be added or removed to produce the 60 wt % solution at its boiling point?